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The 

AWS OFJME-ALTH 




HUTGHISOlf 



Physiology 

Hygiene 
Stimulants 

Narcotics 




English Classics, 



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f 



V 



'V 



s 




THE VISCERA 
IN POSITION. 



THE 



Laws of Health 



Physiology, Hygiene, 
Stimulants, Narcotics. 



EDUCATIONAL INSTITUTIONS and GENERAL READERS. 



Copiously Illustrated. 




-S^ 



Joseph C. Hutchison, M.D., LL..D , 

AUTHOR OF A TREATISE ON PHYSIOLOGY AND HYGIEN^ ; EX-PRESIDENT OF THE NEW 

YORK PATHOLOGICAL SOCIETY ; EX-VICE-PRESIDENT OF THE NEW YORK 

ACADEMY OF MEDICINE ; SURGEON TO THE BROOKLYN CITY 

hospital; late president of the medical SOCIETY 

OF THE STATE OF NEW YORK: ETC., ETC. 



NEW YORK : 

Clark & Maynard, Publishers, 
734 Broadway. 



A TREATISE ON PHYSIOLOGY AND HYGIENE, 

For Educational Institutions and General Readers. 
Fully Illustrated. By Joseph C. Hutchison, M. D., 
Author of "The Laws of Health;" Ex-President of the 
New York Pathological Society ; Vice-President of the 
New York Academy of Medicine, Surgeon to the Brooklyn 
City Hospital ; late President of the Medical Society of 
the State of New York, etc. 



Copyright, 1884, by Clark 6^ Maynard, 



PREFACE 



rPHE object of this work is to present in clear and concise 
language the knowledge of to-day concerning the Laws of 
Health and the effects of Narcotics and Stimulants, as far as 
possible in a work so elementarj'. Enough of Anatomy and 
Physiology has been introduced to enable the pupil to study 
intelligently the laws by which health may be preserved and 
disease prevented. It is specially designed to meet the require- 
ments of Grammar Schools, but is also adapted to those of a 
higher grade. 

A feature of the work is the relation of Stimulants and Nar- 
cotics to the Laws of Health, a subject which is now receiving 
a large share of public attention. Correct instruction upon this 
subject will, it is believed, tend to diminish the use of Stim- 
ulants and Narcotics, and all the bad consequences which 
so frequently follow. 

Great care has been taken to use familiar language as far as 
practicable, but scientific terms not in common use are some- 
times necessarily introduced ; their meaning may be learned by 
referring to the Pronouncing Glossary at the end of the volume. 

The discussion of disputed points has been avoided because 
it would be manifestly inappropriate in a work of this char- 
acter. 



CONTENTS. 



CHAPTER I. 

PAGE 
THE FKAMEWORK OF THE BODY 11 

Tlie Bones — Their Form and Composition — Tlie Properties of 
Bone— The Skeleton — The Joints — The Spinal Column — The 
Growth of Bone — The Repair of Bone. 



CHAPTER II. 

THE MUSCLES 23 

The Muscles — Flexion and Extension — The Tendons — Contrac- 
tion — Physical Strength — Necessity for Exercise — Its Effects 
— Forms of Exercise — Walking — Riding — Gymnastics — 
Open-air Exercise — Sleep — Recreation. 

CHAPTER III. 

THE INTEGUMENT, OR SKIN 31 

The Integument — Its Structure — The Nails and Hair — The Com- 
plexion — The Sebaceous Glands — The Perspiratory Glands 
— Perspiration and its Uses — Importance of Bathing — Differ- 
ent Kinds of Baths — Manner of Bathing — The Benefits of 
the Sun — Importance of Warm Clothing — Poisonous Cos- 
metics. 

CHAPTER IV. 

FOOD AND DRINK 89 



Necessity for Food— Waste and Repair— Hunger and Thirst — 
Amount of Food— Renovation of the Body— Mixed Diet — 
Milk— Eggs — Meat— Cooking — Vegetable Food — Bread— 
The Potato — Fruits— Purity of Water— Action of Water 
upon Lead— Coffee, Tea, and Chocolate— Effects of Alcohol. 



CHAPTER V. 

DIGESTION 57 

The Principal Processes of Nutrition— The General Plan of Di- 
gestion—Mastication—The Teeth— Preservation of the Teeth 



CONTENTS* 



— Insalivation — The Stomacli and the Gastric Juice — The 
Movements of the Stomach — Gastric Digestion — The Intes- 
tines — The Bile and Pancreatic Juice — Intestinal Digestion — 
Absorption by means of Blood-vessels and Lacteals — The 
Lymphatic or Absorbent System — The Lymph — Conditions 
which affect Digestion — The Quality, Quantity, and Temper- 
ature of the Food — The Influence of Exercise and Sleep. 



CHAPTER VI. 

THE CIRCULATION 75 

The Blood — Its Plasma and Corpuscles — Coagulation of the Blood 
— The Uses of the Blood — Transfusion — Change of Color — 
The Organs of the Circulation — The Heart, Arteries, and 
Veins — The Cavities and Valves of the Heart — Its Vital 
Energy — Passage of the Blood through the Heart — The Fre- 
quency and Activity of its Movements — The Pulse — The 
Capillary Blood-vessels — The Rate of the Circulation — 
Assimilation — Injuries to the Blood-vessels. 



CHAPTER Vn. 

RESPIRATION 91 

The Objects of Respiration — The Lungs — The Air-Passages — 
The Movements of Respiration — Expiration and Inspiration 
— The Frequency of Respiration — Capacity of the Lungs — 
The Air we Breathe — Changes in the Air from Respiration — 
Changes in the Blood — Interchange of Gases in the Lungs — 
Comparison between Arterial and Venous Blood — Respira- 
tory Labor — Impurities of the Air — Dust — Carbonic Acid — 
Effects of Impure Air — Nature's Provision for Purifying the 
Air — Ventilation — Animal Heat. 



CHAPTER Vm. 

THE NERVOUS SYSTEM 106 

Animal and Vegetative Functions— Sensation, Motion, and Voli- 
tion — The Structure of the Nervous System — The White 
and Gray Substances — The Brain — Its Convolutions — The 
Cerebellum — The Spinal Cord and its System of Nerves — 
The Anterior and Posterior Roots — The Sympathetic System 
of Nerves — The Properties of Nervous Tissue — Excitability 
of Nervous Tissues — The Functions of the Spinal Nerves 
and Cord — The Direction of the Fibres of the Cord — Reflex 
Activity and its Uses — The Functions of the Medulla Oblon- 
gata and the Cranial Ganglia — The Reflex Action of the 
Brain. 



CONTENTS. 7 

CHAPTER IX. 

PAGE 

THE SPECIAL SENSES 130 

The Production of Sensations — Variety of Sensations — General 
Sensibility — Pain and its Function — Special Sensation, 
Touch, Taste, Smell, Sight, and Hearing — The Hand, the 
Organ of Touch — The Sense of Touch — Delicacy of Touch — 
Sensation of Temperature and Weight — The Tongue the 
Organ of Taste — The Nerves of Taste — The Sense of Taste, 
and its Relations with the other Senses — The Influence of 
Education on the Taste — The Nasal Cavities, or the Organs 
of Smell — The Olfactory Nerve — The Uses of the Sense of 
Smell— The Sense of Sight— Light— The Optic Nerve— The 
Eyeball and its Coverings — The Function of the Iris — The 
Sclerotic, ( 'horoid, and Retina — The Tears and their Func- 
tion — The Movements of the Eyeball— The Function of Ac- 
commodation — The Sense of Hearing and Sound — The Ear, 
or the Organ of Hearing — The External, Middle, and Inter- 
nal Ear. 

CHAPTER X. 

THE YOICE 168 

Vc ice and Speech — The Larynx, or the Organ of the Voice — The 
Vocal Cords — The Laryngoscope — The Production of the 
Voice — The Use of the Tongue — The different Varieties of 
Voice — The Change of Voice — Its Compass — Purity of Tone 
— Ventriloquism. 

Appendix 177 

Poisons and their Antidotes 177 

Drowning 180 

Care of the Sick-room 181 

Disinfection 183 

Emergencies 185 

Home and Health 188 

On Going into the Country 191 

Glossary , 193 



LIST OF ILLUSTRATIONS. 



Fig. pagk 

Frontispiece— Viscera in Position 

1. Section of bone 12 

2. Structure of bone, magnified , 13 

3. The skeleton 15 

4. Elbow-joint 16 

5. Spinal column 17 

6. Muscular tissue, magnified 25 

7. Root and transverse section of hair, magnified 83 

8. Granules of potato starch 44 

9. Section of the trunk 58 

10. Section of a tooth 59 

11. Section of the jaws 60 

12. Section of the jaws— right side 61 

13. Structure of a salivary gland 62 

14. Head of a horse, showing salivary gland, etc 63 

15. Section of chest and abdomen 65 

16. Organs of digestion 66 

17. Thelacteals 70 

18. Blood corpuscles 76 

Circulation of the blood opposite 78 

19. Heart and large vessels 78 

20. Section of the heart 79 

2L Valves of the Veins 84 

22. Web of frog's foot, magnified 85 

23. Circulation in a frog's foot 85 

24. Organs of the chest 92 

25. Larynx, trachea, and bronchial tubes 93 

26. Diagi-am of the structure of the air-cells 93 

27. Section of the lungs 94 

28. Section of mouth and throat 95 

29. Cerebi'o-spinal system 108 

30. Upper surface of the cerebrum 110 

31. Vertical section of the brain Ill 

32. Base of the brain 112 

'6?,. Brain and spinal cord 113 

34. Sense of touch 136 

35. Section of nasal cavity 143 

30. Front view of the eye 147 

37. Vertical section of the eye 148 

38. Retinal image 154 

39. Different shapes of the globe of the eye 155 

40. Function of accommodation 156 

41. Diagram of the ear and its parts 159 

42. Section of the ear 162 

43. Section of larynx and trachea 171 

44. View of voc^l cords by the laryngoscope 172 

45. Different positions of vocal cords 173 



The Laws of Health. 



CHAPTER I. 

The Framework of the Body. 

The Bones — Their Uses — Their Size and Shape — Their 
Structure and Connposition — ^The Properties of Bone — 
The Skeleton — The Joints and Motion — The Spinal 
Column — The Repair of Bone — Changes in the Skeleton. 

1. The Bones. — The human body is the house in which the 
soul of man dwells during life. When life ends and the soul 
takes its departure, its temporary home speedily falls to pieces ; 
some parts of it sooner, some later. As in a mansion that has 
been allowed to go to decay, or has been wasted by fire, the 
frail portions perish, while the masonry, the walls and the stouter 
timbers remain, so in the untenanted body, its stronger, harder 
parts, the hones, outlast the softer ones, — those by means of 
which we feel, breathe and move. 

2. The Uses of the Bones. — The bones supply the founda- 
tion, frame and rafters of the house in which we live. They 
determine and preserve the general outline and size of the 
body. They give rigidity to the limbs, so that movements are 
possible, and also serve as a protection to the more delicate and 
important parts. 

The more delicate the organ, the more completely does 
Nature shield it. For example : the brain, which is soft in 
texture, is enclosed on all sides by a spherical box of bone ; the 



12 



THE FRAMEWORK OF THE BODY. 



eye, though it must be near the surface of the body to command 
an extensive view, is sheltered from injury within a deep recess 
of bone; the lungs, requiring freedom of motion as well as 
protection, are surrounded by a mobile " chest " composed partly 
of bone and partly of muscle. 

3. The Size and Shape of the Bones. — Kearly every 
scientific principle known in architecture was anticipated by 
the Divine hand which framed our bodies long before human 
science began to exist. The size and form of the bones vary 
greatly in different parts of the body. There are, however, but 
three general classes : the loiig bones, such as those of the 
limbs ; the sliort, as in the "\vrist ; and the fiat, like the shoulder- 
blade. The long bones are commonly round and hollow at their 
middle portion, as greater degree of strength is furnished by the 
same amount of material, if it is in the form of a tube, than if 
it is a solid pillar of the same length, 

4. The Structure of Bone. — Let us examine one of the 
long bones after it has been sawed through lengthwise (Fig. 1.) 




Section of Bone 



We notice the hollow central cavity, containing an oily sub- 
stance, called the marrow. We find that the outer surface is 
hard like ivory, and is pierced here and there with small open- 
ings for the admission of blood-vessels. The interior, especially 
at the ends, is comparatively light and porous, the slender fibres 
interlacing like miniature lattice-work. So that, although a 



THE FRAMEWORK OF THE BODY. 



13 





Fig. 2. 






■ 


1 




^^^B 


fc 




^^B 


H 




^^^y 


H 




^^^l^B 


^B 




^^■H 


^H 




^^^mmimm 


^^^ 



Structure of Bone En- 
larged. 



bone be as hard as stone externally, it is by no means as 
heavy. If a thin section of bone be examined under the 
microscope, we discover that it is pierced by numerous fine 
tubes (Fig. 2), about wliich layers of bone-substance are ar- 
ranged. By means of these tubular pas- 
sages the blood-vessels, which nourish 
the bones, run to and fro through their 
inner structure. 

5. The Composition of Bone. — 
Bone is partly a mineral and partly an 
animal substance, united in the propor- 
tion of two parts of the former with one 
of the latter. Each of these substances 
may be separated from the other for ex- 
amination. First, if we expose a bone 
to the action of fire, the animal matter, 
.which is called gelatine, is driven off, or 
"burned out." We now find that al- 
though the shape of the bone remains the same, that which is 
left is quite brittle and will not sustain weight as before. 
Again, we may remove the mineral ingredient, which is a form 
of lime, by placing a second piece of bone in a dilute acid. 
The lime is thus dissolved away, leaving the shape the same. 
The bone is now no longer stiff and hard, but is flexible; 
and if a long and thin bone, a rib for example, has been made 
use of in the experiment, it may be tied in a knot without 
breaking. In early life the bones contain more of the animal 
substance ; in old age, more of the mineral. Hence the bones 
of the young, although exposed to a great variety of accidents, 
do not break readily ; and when broken unite rapidly. On the 
the other hand, the bones of old persons are decidedly brittle, 
and when broken, do not always unite well and quickly. 

6. Properties of the Bones. — From these facts, made 
known to us by chemistry and the microscope, we learn that 
the bones are not so simple and uiiiuteresting as at first appears, 



14 THE FRAMEWORK OF THE BODY. 

but are adapted with wonderful care and skill to all the pur- 
poses they are designed to serve. They are strong, but not 
heavy ; hard, but not brittle ; somewhat elastic by reason of the 
gelatine, and yet solid and firm by reason of the lime. Their 
exposed portions are so made as to be dense and resisting, while 
the interior is more sponge-like and well furnished with blood- 
vessels which nourish and cause them to live. 

7. The Skeleton. — The bones of the human body are about 
200 in number, each of which is known to the anatomist by its 
appropriate name. A few of these names are marked upon the 
accompanying engraving (Fig. 3.) All these bones when united 
together in their natural relations form the Skeleton. The 
greater number of the bones are arranged in pairs, one of each 
kind on each side of the frame. The skeletons contain three 
important cavities. 

The first of these surmounting the frame, is a box of bone, 
called the skull ; below this, is a hooped case, or "chest;" and 
lower down is a bony basin, called the pelvis. The two latter 
compose the "trunk." The trunk and skull are maintained in 
their proper relations by the " spinal column." Branching from 
the trunk are two sets of limbs : the arms, which are attached 
to the chest by means of the "collar-bone" and "shoulder- 
blade;" and the legs, directly joined to the lower part of the 
trunk. 

8. These three cavities are designed for the lodgment and 
protection of the more delicate and perishable parts of the sys- 
tem. Thus, the skull together with the bones of the face, 
shelter the brain and the organs of four senses — sight, hearing, 
smell, and taste. The chest contains the heart, lungs, and great 
blood-vessels, while the lower part of the trunk holds and 
shields a variety of organs, chiefly those concerned in nourishing 
the body. 

9. The Joints. — The point of union of two or more bones 
forms a joint, or articulation, the connection being made in 
various ways according to the kind and amount of motion de- 




Fig, 3.— The Skeleton. 



16 



THE FRAMEWORK OF THE BODY. 



sired. The movable joints are connected by strong fibrous 
bands, called ligaments. These ligaments are of a silvery- 
whiteness, and very unyielding ; so much so, that the bone to 
which a ligament is attached may be broken, while the ligament 
itself remains iminjured. T^Tien this connecting material of 
the joints is strained or lacerated by an accident, a " sprain " is 
the consequence. An injury of this sort frequently is quite as 
serious as the breaking of a bone. 

10. Motion in the Joints. — The ligaments then make the 
joints firm and strong. How are they rendered flexible and 
easy of motion ] In the first place, the bones are made some- 
what broad and flat at the ends, and are so formed that one will 
fit into the other. In the next place, these fitted surfaces are 




Fig. 4. — Elbow Joint. A, Bone of the ann ; B, C, Bones of the fore-arm. 



covered with a thin layer of " cartilage," an elastic and exceed- 
ingly smooth material, which not only enables them to move 
easily over each other, but also serves, like the springs of a 
carriage, to deaden the force of jolts and jars. A third provi- 
sion for smooth motion is the introduction between the ends of 



THE FRAMEWORK OF THE BODY. 



17 



the bones of a thin sac, containing a fluid resembling the white 
of egg. This fluid serves the same end in the joints, as the 
oil that is used on the wheels of a carriage ; it diminishes wear 
and noise and friction. But it is self-supplied, and flows only 
so fast as it is used up by the motions of the joint. (Bead 
note, end of chapter.) 

11. The Spinal Column. — The spinal column 
is commonly called the "back-bone," as if it 
were a single bone, whereas it really consists of 
a chain of 26 small bones, named vertehroe. It 
is channeled out for the reception of the spinal 
cord. (Fig. 5.) 

12. The joints of the vertebrae are remark- 
able for the thick layers of cartilage which 
separate the adjacent surfaces of bone. The 
amount of motion between any two of these 
bones is not great ; but these little movements, 
taken together, admit of very considerable 
flexibility in several directions. The abundant 
supply of these cartilages adds greatly to the 
elasticity of the frame. It is due, in part to 
this elastic material, and in part to the frequent 
curves of the spine, that the brain and other 
delicate organs are not more frequently injured 
by the shock of sudden falls or missteps. Dur- 
ing the day, the constant pressure upon these 
joints, while the body is erect, diminishes the 
thickness of the cartilages ; so that a person is 
not so taU in the evening as in the morning. 
The effects of this compression pass away when 
the body is in a reclining posture. 

13. The Growth of Bone. — The bones, like 
all other parts of the body, are constantly 
undergoing change, worn out material being 
withdrawn to make room for a fresh supply. 



Fig. 5.— The 
Spinal Column. 



This cliange 



18 THE FRAMEWORK OP THE BODY. 

has been shown conclusively by experiment. If an animal 
be fed with madder — a red coloring matter — for a day or two 
the bones soon become tinged ; then, if the madder be discon- 
tinued for a few days, the original color returns. If, however, 
this material be alternately given and withheld at short inter- 
vals, the bone will be marked by alternate rings of red and 
white. In a very young animal, all the bones become red in a 
single day ; in old ones, a longer time is necessary. The pro- 
cess of waste and repair in the hard bones, therefore, is con- 
stantly taking place and with astonishing rapidity. 

14. The Repair of Bone. — Nature's provision for uniting 
broken bones is very complete. At first, blood is poured out 
around the ends of the bone, as a result of the injury. This is 
gradually absorbed and gives place to a watery fluid, which, 
thickening from day to day, acquires at the end of two weeks 
the consistency of jelly. This continues to harden by the 
deposit of new bone-substance until, at the end of five or six 
weeks, the broken bone may be said to be united. It is, how- 
ever, still fragile, and must be used carefully a few weeks 
longer, but months pass before the union can be said to be com- 
plete. When firmly united, the bone is very strong, and if 
another accident happens to it, it is quite as liable to break in 
some new place as at the point of union. 

15. Changes in the Skeleton. — Man does not reach his full 
height until he is about twenty-five years old ; and even after 
that age, the bones continue to increase in strength and hard- 
ness. Before that age, they are comparatively soft and flexible, 
by reason of the gelatin they contain. This is especially true in 
childhood ; and it is fortunate that it is so, since that condition 
is much more favorable to the steady and rapid growth of the 
bones than if they contained more of the lime, as is the case in 
old age when there is no occasion for change in the size or 
shape of the skeleton. The skull, however, is said to increase 
slightly in size even in advanced life in those persons in whom 
the brain is continually employed in thought or study. How- 



THE FRAMEWORK OF THE BODY. 19 

ever, this very flexibility of the bones, in early life, which favors 
their steady growth and prevents their breaking easily, is some- 
times the source of serious deformity. A young child may be 
allowed to stand and walk too early, and as a consequence, the 
lower limbs become permanently bent inward, in the distortion 
called "knock-knees," or outward, as in "bow-legs." For the 
same reason, a bent position of the spinal column, permitted to 
exist habitually in childliood, may result in a life-long de- 
formity. 

16. The Erect Posture. — Youth is, in a great measure, the 
forming as well as the growing period of the frame. Bad habits 
of posture, early formed, become fixed in later life, and their 
results — as seen in contracted chests and round shoulders — are 
with difficulty remedied. Eight habits, on the other hand, 
tend to produce an erectness of posture which is favorable, not 
alone to strength and health, but also to grace and ease. The 
following directions should be learned and practiced : hold the 
head erect with the chin somewhat near the neck ; expand the 
chest in front ; throw the shoulders back, keeping them of the 
same height on both sides ; maintain the natural curves of the 
spine, as shown in the last figure. Man alone, of all the ani- 
mals, has the power to stand and move in the erect posture. 



NOTE. 
How Joints may be Injured (p. 16, IT 10).—" All the joints are liable to dis- 
location—that is, being 'put out' of their place. Owing to the shallowness of the 
cavity at the shoulder, this joint is frequently dislocated ; and this sometimes happens 
with the thigh, but not so often, as the cup in which the femur moves is much deeper. 
Joints which have been dislocated should at once be ' set ;' but now that you have seen 
how liable you are to accident, I hope you will be careful not to indulge in too violent 
or rough exercise, by which you might not only dislocate the joints, and so in time 
weaken them, but might also break the bones, and perhaps become crippled for life. 
Many children have the habit of pulling their fingers so as to make them ' crack." This 
is exceedingly wrong, for it is to a certain extent pulling the joints out of their sockets, 
and this may so loosen the parts as to cause permanent injury."— Davidson's "Our 
Bodies." 



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22 THE FRAMEWORK OF THE BODY. 

QUESTIONS FOR TOPICAL REVIE^A^. 

PAGE 

1. What useful purposes do the bones serve ? 11^ 12 

2. "What can you say of the size and shape of the bones ? 12 

3. State what you can of the structure of the bones 12 

4. State what you can of the composition of the bones 13 

5. Of the usefulness of mineral substance in the bones 13, 14 

6. Of the usefulness of animal substance in the bones 13, 14 

7. Of the strength belonging to the bones 18 

8. How many bones in the human body ? 14 

9. What is meant by the human skeleton ? 14 

10. Give a description of its construction 15 

11. Name the important cavities in a skeleton 14 

12. How are the trunk and skull kept in position ? 14 

13. Name the limbs 14 

14. What is meant by a joint in the human frame ? 15 

15. State what you can of the movable joints 16 

16. What office is performed by the ligaments of the joints ? 16 

17. What by the cartilage at the joints? 1 17 

18. Describe the construction of the spinal column 17 

19. What properties and powers does the spinal column possess ? 17 

20. When is a person taller than at other times ? 17 

21. Give the reason for this 17 

22. Describe the process by which a broken bone is repaired 18 

23. At what age does man reach his height ?. 18 

24. Why is deformity more liable to occur in the young than after maturity ?. . . 19 

25. What causes "knock-knees" and "bow-legs?" 19 

26. What is said of posture ? and what is the correct position? 19 



NOTE. 

Some Properties of Bone.— The power of bone to resist decay is remarkable. 
Fossil bones deposited in the ground long before the appearance of man upon the earth 
have been found by Cuvier exhibiting a considerable portion of cartilage. The jaw of 
the Cambridge mastodon contained over forty per cent, of animal matter— enough to 
make a good glue— and others about the same. From this we see that a nutritious 
soup might be made from the bones of animals that lived before the creation of man. 
The teeth resemble bone in their structure, but resist decay longer ; they are brought 
up by deep-sea dredging, when all other parts of the animal have wasted away. The 
bones differ at dififerent ages, and under different social conditions. In the disease 
called "rickets," quite common among the ill-fed children of the poor in Europe, but 
somewhat rare in America, there is an inadequate deposit of the mineral substance, 
rendering the bones so flexible that they may be bent almost like wax. In females and 
weak men the bones are light and thin, while in a powerful frame they are dense and 
heavy. Exercise is as necessary to the strength of bone as to the strength of muscle ; 
if a limb be disused, from paralysis or long sickness, the bones lose in weight and 
strength as well as the soft parts. Bone is said to be twice as strong as oak, and, to 
crush a cubic inch of it, a pressure equal to 5,000 pounds is requisite. 



CHAPTER II. 

The Muscles. 

Movements of the Body — The Muscles — Flexion and Exten- 
sion — The Tendons — Contraction — Physical Strength — 
Relative Strength of Animals — Physical Culture — Neces- 
sity for Exercise — Its Effects — Forms of Exercise — Exces- 
sive Exercise — Walking — Riding — Gymnastics — Open-air 
Exercise — Sleep — Recreation. 

1. Movements of the Body. — We have seen that, in some 
respects, the human body resembles a house built for the soul 
to dwell in. But, inasmuch as its walls are flexible and its 
foundation is movable, it is something more than a house ; in 
some respects, it may be likened to a machine. The body has 
the power of motion, as when we swing the arm ; it is also 
capable of locomotion, as when we walk or run from one place 
to another. The machinery which effects these and many other 
movements is the muscles. The word muscle means " a little 
mouse," and is supposed to refer to the peculiar sensation pro- 
duced, as of a small moving body, when a muscle is felt in 
action ; for example, grasp the upper portion of the arm while 
the elbow-joint is caused to move to and fro. The burrowing 
motion then felt in the front of the arm is caused by the action 
of the "biceps" muscle (Fig. 6). This is the muscle which, 
in the arm of the blacksmith, becomes so large and powerful. 

2. Tlie Muscles, op the Flesh. — The muscles, nearly four 
hundred in number, form the great bulk of the body external 
to the skeleton. They largely determine its weight and outline. 
They are nearly all designed to move the bones, but a few act 



24 



THE MUSCLES. 



upon the softer parts ; for example, those that move the eye, 
eyelids and lips. 

3. The Tendons. — Tendons, or sinews, are the extremities 
of muscles, and are firmly fastened upon the bones. They are 
very strong, and of a silvery whiteness. They may be felt just 
beneath the skin, when the muscles are being used, as at the 
bend of the elbow or knee. The largest tendon of the body 
is that which is inserted into the heel, called the tendon of 
Achilles, after the hero of the Grecian poet, the fable relating 
that it was at this point that he received his death-wound, no 
other part of his body being vulnerable. 

4. Structure of the Muscles. — The muscles are composed 
of a soft substance, of a deep red color, which closely resembles 
the lean meat of beef. Under the microscope, we observe that it 

is composed of layers 
and bundles of small 
fibres. And these are, 
in turn, made up of 
still finer fibres, called 
fihrUlce (Fig. 8). The 
fibres are beautifully 
marked by regular cross 
lines, or stripes, about 
ten thousand to an 
inch. These circular 
markings are always 

present in the voluntary muscles, and hence they are known 

as the " striped " muscles. 

5. Voluntary and Involuntary Muscles. — The muscles are 
divided into two classes, the voluntary and the involuntary. In 
the first class are those which are used only when we wish or 
will to use them — as the muscles of the hand or arm. The 
second includes those which are not under the control of the 
mind. The heart is a muscle of the involuntary variety. We 
cannot change its action by an effort of the will. " During pro- 




FiG. 6. — Muscular Tissue. 

a, b, Striped muscular fibres ; c, The same more 

highly magnified. 



THE MUSCLES. 25 

found sleep, when the will is entirely at rest, the heart con- 
tinues to beat without cessation. The muscles concerned in 
breathing are partially under our control, but they are chiefly 
involuntary, and, therefore, continue to act while the mind is 
at rest or is fully occupied in work or play. 

6. Muscular Contraction. — Whenever a muscle is caused to 
act it undergoes contraction, or a change of form, by which its 
two ends are brought more nearly together. The raising of the 
arm, the bending of the finger and most of the ordinary move- 
ments of the limbs are effected by the will ; but the will is not 
the only means of producing muscular action. Electricity, or a 
sharp blow over a muscle will also produce it. 

7. Contraction is not the permanent state of a muscle. It 
cannot long remain contracted, but after a shorter or longer 
time, it wearies and is obliged to relax. After a short rest it 
can then again contract. For this reason, it is more fatiguing 
to stand for any great length of time in one position, than to be 
walking. 

8. Relative Strength of Animals. — The amount of muscular 
power which different animals possess has been tested by ex- 
periment. It is found that man is able to drag a little less 
than his own weight. A draught-horse can exert a force equal 
to about two-thirds of his weight. The horse, therefore, though 
vastly heavier than man, is relatively not so powerful. Insects 
are remarkable for their power of carrying objects larger and 
heavier than themselves. Many of them can drag ten, and 
even twenty times their weight. Some of the beetles have 
been known to move bodies more than forty times their own 
weight. 

9. Physical Strength. — The diff'erence in strength, as seen in 
different individuals, is not due to any original difference in 
their muscles. Nature gives essentially the same kind and 
amount of muscles to every healthy person, and the power of 
one, or the weakness of another, arises, in great part, from the 
manner in which these organs are used or disused. 

2 



26 THE MUSCLES. 

10. Importance and Effects of Exercise. — Action is the 
law of the living body. Every organ demands use to pre- 
serve it in full vigor, and to obtain from it its best services. 
Exercise consists in a well-regulated use of the voluntary 
muscles, but its effects are not limited to the parts used. Other 
organs are indirectly influenced by it. The heart beats more 
rapidly, the skin acts more freely, the brain is invigorated, and 
the appetite and power of digestion are increased. 

11. The first effects of exercise, however, are upon the muscles 
themselves. If we examine a muscle thus improved by exer- 
cise, we find that its fibres have become larger and more closely 
blended together, that its color is of a darker red, and that the 
supply of blood-vessels has increased. Without exercise the 
muscle appears thin, flabby, and pale. On the other hand, 
excessive exercise, without sufficient relaxation, causes a similar 
condition. The muscle then becomes flabby and weak, because 
it is worn out more rapidly than nature builds it up. 

12. Violent exercise is not beneficial, as strength is the 
result of a gradual growth. To gain the most beneficial results, 
the exercise should be at regular hours and during a regular 
period, the activity and the time varying with the strength of 
the individual and measured by it. 

13. Different Modes of Exercise. — There are very few who 
have not the power to walk. There is required for it no ex- 
pensive apparatus, nor does it demand a period of preliminary 
training. Walking may he called the universal exercise. With 
certain foreign nations, the English especially, it is a very 
popidar exercise, and is practised habitually by almost every 
class of society. Running, leaping, and other more rapid and 
violent movements, are the forms of exercise that are most 
enjoyed in childhood. For the child, they are not too severe, 
but they may be so prolonged as to become injurious. Instances 
have been recorded where sudden death has resulted after 
violent playing, from overtaxing the heart : for example, we 
have the case of a young girl who, while skipping the rope, and 



THE MUSCLES. 27 

endeavoring to excel her playmates by jumping the greatest 
number of times, fell dead from rupture of the heart. 

14. Carriage-riding is particularly well suited to invalids, and 
to persons advanced in life. Horseback exercise brings into use a 
greater number of muscles than any other one exercise, and 
with it there is an exhilaration of feeling which refreshes the 
mind at the same time. That form of exercise which interests 
and diverts the mind will yield the best results ; and as many sets 
of muscles should be employed as possible, open-air exercise be- 
ing the best. No in-door exercise, however excellent in itself, 
can fill the place of hearty and vigorous activity in the open 
air. 

15. Excessive Exercise. — If neglect of exercise is injurious, 
so also is the excess of it. Violent exertions do harm; they 
often cause undue strain, and even lasting injury to some part 
of the body. For this reason the spirit of rivalry which leads 
to tests of endurance and feats of strength should be discouraged. 
Those trials of the muscles, especially, which are supposed to 
demand " training " should not be encouraged. Training, it is 
true, can produce a remarkable muscular development, so that 
nearly every muscle of the limbs is as large and corded as the 
arm of a blacksmith, but it is too often at the expense of some 
internal, vital organ. Large muscles are not a certain index of 
good health. It was well known by the ancients that athletes 
of their day were short-lived, notwithstanding the perfection of 
the physical training then employed. When a person over- 
tasks the heart, or, in other words, " gets out of breath," he 
should regard it as a signal to take rest. It is well known that 
both horses and men, after having been brought into " condi- 
tion " for competitive trials, soon lose the advantages of their 
training after the occasion for it has passed. 

16. Rest. — We cannot always be active : after labor we must 
rest. We obtain this rest partly by suspending all exertion, as 
in sleep, and partly by change of employment. It is said that 
Alfred the Great recommended that each day should be divided 



28 THE MUSCLES. 

in the following manner : " Eight hours for work, eight hours 
for recreation, and eight hours for sleep." This division of 
time is as good as any that could now be made, if it be borne 
in mind that, when the work is physical, the time of recreation 
should be devoted to the improvement of the mind ; and when 
mental, we should then recreate by means of physical exercise. 

17. During sleep, all voluntary activity ceases, the rapidity of 
the circulation and breathing diminishes, and the temperature 
of the body falls one or two degrees. In consequence, the 
body needs warmer coverings than during the hours of wakeful- 
ness. During sleep, the body seems wholly at rest, and the 
mind is also inactive, if we except those involuntary mental 
wanderings which we call dreams. iS'evertheless it is not an 
idle period. Nutrition, or the nourishing of the body, now 
takes place. A^Tiile the body is in action, the process of pulling 
down predominates ; but in sleep, that of building up is more 
active. If sleep is insufficient, the effects are seen in the lassi- 
tude and weakness which follow. 

18. All persons do not require the same amount of sleep, but 
most men need from seven to nine hours. Frederick the 
Great required only five hours of sleep daily, and Bonaparte 
could pass days with . only a few hours of rest. But this long- 
continued absence of sleep is attended with danger. After loss 
of sleep for a long penod, in some instances, stupor has come 
on so profoundly, that there has been no awaking. 

19. There are instances related of sailors falling asleep on the 
gun-deck of their ships while in action. On the retreat from 
Moscow, the French soldiers would fall asleep on the march, 
and could only be aroused by the cry, " The Cossacks are 
coming ! " Tortured persons are said to have slept upon the 
rack in the intervals of their torture. In early life, while 
engaged in a laborious country practice, the writer not infre- 
quently slept soundly on horseback. These instances, and 
others, show the imperative demand which nature makes for 
rest in sleep. 



TABLE OF THE PRINCIPAL MUSCLES. 



Tlie Head. 



Oc-cip'i-to— fron-ta'lis, moves the scalp and eyebrows. 
Or-bic-u-la'ris pal'pe-brae, closes the eye. 
Le-va'tor pal'pe-brae, opens the eye. 
The Recti muscles (4 in number), move the eye-ball. 

Kfe°ter!'}-^«^^^-l«--J-- 



The Neck. 

Sca-le'ni muscles move the neck from side to side. 

The Trunk. 

Pec-to-raT.is, moves the arm forwards. 

La-tis'si-mus dor'si, moves the arm backwards. 

Tra-pe'zi-us, ) 

Ser-ra'tus mag-'nus, Vmove shoulder-blade. 

Rhom-boi de'us j 

In-ter-cos'tals, move the ribs in respiration. 

Erec'tor spi'nae, move the trunk backwards. 



The Upper Iiinib. 



Del'toid, raises the arm. 
Te'res ma'jor, lowers the arm. 

I^?'^^^^?;<='^'^^''''^' [i-otate the arm. 
Spi-na'tus, ) 

Bi'ceps, bends forearm. 

Tri'ceps, straightens forearm. 

Flex'or car'pi ra-di-a'liS: 
ul-na'ris, 



Exten'sor car-pi ra-di-a'lis, 



move the hand. 



ul-na'ris 

More than 30 muscles take part in moving the flngerSo 

The Lio-wer liimh. 

Il-i'a-cus, ) 

PeSfnS^s'"""' ■"»- ">» thigh forward,. 

Ad-duc'tor, } 

P^lSSm'is, h""^^^ *^^ *^'^^^ backwards. 

Sar-to'ri-us (from Sar'tor, a tailor), crosses one thigh over the otlier. 

Vas'tus, i "^"'^^ *^^ ^^^ forwards. 

GraclSis, ) ^^"^^ *^^ ^^^ backwards. 
Tib-i-a'lis, \ 

Per-o-ne'us, ( xi x. i. 

Gas-troc-ne'-mi.us, h ^ove the foot. 
So-le'us, ) 

Twenty muscles take part in moving the toes. 



30 THE MUSCLES. 

QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1. State what you can of the movements of the body 23 

2. What can you state of the number and division of the muscles ? 23 

3. What is the office of the muscles ? 23 

4. Describe the structure of the muscles 24 

5. Which is the largest tendon in the body ? 24 

6. What is the difference between voluntary and involuntary muscles ? 24 

7. Illustrate the difference between the two 24, 25 

S. State all you can of the tendons or sinews 25 

9. What is meant by contraction of the muscles ? o 25 

10. In how many and what ways may contraction be effected ? 25 

11. Why cannot a muscle in life continue contracted for a long time ? 25 

12. How does the sti'ength of a man compare ^^ith that of a horse ? 25 

13. "^Tiat can you state in relation to the relative sti'ength of animals ? 25 

14. What, in relation to physical strength ? 25 

15. What, in relation to the importance of exercise ? 26 

16. Wliat is the effect of exercise upon the heart, skin, and appetite ? 26 

17. How does exercise affect the current of the body's circulation ? 26 

IS. How does judicious exercise affect the muscles ? 26 

19. What is stated of violent and spasmodic exercise ? 26 

20. Of the exercise of walking ? 26 

21. Of running, leaping, and other modes of exercise ? 26 

22. Of the importance of rest from labor or exercise ? 27 

23. What is the effect of excessive exercise ? 27 

24. What commonly follows training ? .-• 27 

25. What processes take place during sleep ? 28 

26. What effects follow insufficient sleep ? 28 

27. How many muscles in the head ? 29 

28. How many in the neck? 29 

29. How many in the tmnk? 29 

30. How many muscles take part in moving the fingers ?. 29 

31. How many in moving the toes ? 29 

NOTE. 
The 111 Effects of Over-exertion.—" It should be recollected that the action 
of the muscles has limits, as Avell as that of every other organ of the body. The 
muscles and the heart may be taxed too severely, and permanent derangements may be 
produced by overtaxing the human body. The ancient gJ^nnasts among the Greeks are 
said to have become prematurely old, and the clowns (or acrobats) and athletes of our 
own days suffer from the severe strain put upon their muscular systems." The effects 
of boat-racing in England have been thus described by Mr. Skey, an eminent surgeon : 
"The men look utterly exhausted. Their white and sunken features and pallid lips 
show .serious congestion of the heart and lungs, and the air of weakness and lassitude 
makes it a mar^•el how such great exertion should have been so nobly undergone. We 
have repeatedly seen the after ill-effects— spitting of blood, congested lungs, and weak- 
ness of the heart from over-distension." "Persons should neither walk, run, leap, or 
play at any game, to the extent of producing iiermanent or painful exhaustion. AH 
exercise should be attended with pleasurable feelings ; and when pain is produced by 
proper exercise, those who suffer should rather seek medical ad\ice than persevere in 
exercise." — Lankester's Manual of Health. 



CHAPTER III. 

The Integument, or Skin. 

The Skin — Its Structure — Its Changes or Growth — The Nails 
and Hair — The Complexion — The Sebaceous Glands — 
The Perspiratory Glands — Perspiration and its Uses — 
Importance of Bathing — Different kinds of Baths — Man- 
ner of Bathing — The Benefits of the Sun — Importance 
of Warm Clothing — Poisonous Cosmetics. 

1. The Skin. — The skin is the outer covering of the body. 
The parts directly beneath it are very sensitive, and without its 
protection life would be an agony, as is shown whenever by 
accident the skin is broken or torn off, the bared surface being 
very tender and sensitive even to exposure to the air. 

2. The Structure of the Skin. — When examined closely, 
the skin is found to be made up of two layers — the outer and 
the inner. The inner one is called the cutis, or true skin ; the 
outer one is the epidermis, or scarf-skin. The latter is also 
known as the cuticle. These two layers are closely united, but 
they may be separated from each other. This separation takes 
place whenever, from a burn, or other cause, a blister is formed; 
a watery fluid is poured out between the two layers, and lifts 
the epidermis from the true skin. 

3. The Scapf-Skin. — Of the two layers, the outer is the 
thinner one, and has the appearance of a whitish membmne. 
It is tough and elastic ; it has no feeling and does not bleed 
when cut. On the palm of the hand, where the scarf-skin is 
especially thick, a needle may be run in and out of it M'ithout 
causing pain or drawing blood. If it be magnified, it will be 



32 THE INTEGUMENT. 

found to be composed of numberless flat cells, or scales, arranged 
layer ujDon layer. Its thickness varies in different parts of 
the body. Where exposed to use, it is thick and horn-like, 
as may be seen on the soles of the feet, or on the palms of the 
hands of those who are accustomed to perform much manual 
labor. 

4. The Cutis, op True Skin. — This layer lies beneath the 
scarf-skin. It is firm, elastic, very sensitive, and is freely sup- 
plied with blood-vessels. Hence a needle entering it not only 
produces pain, but draws blood. It is closely connected with 
the tissues below it, but may be separated by means of a sharp 
instrument. The surface of the cutis is not smooth, but is 
covered here and there with minute elevations, called papilloe. 
These are arranged in rows, or ridges, such as those which can 
be seen plainly in the palm and thumb ; their number is about 
80 to the square line (a line being one-twelfth of an inch). 
These papillce contain blood-vessels and nerves, and are largely 
concerned in the sense of touch ; hence they are abundant where 
the touch is most delicate, as at the ends of the fingers. 

5. Changes in the Skin. — Like all other parts of the body, 
the scarf-skin is constantly being worn out ; it dries, shrivels 
and falls from the body in the form of fine flakes, or scales. In- 
the scalp, these scales form the " dandrufi"." As fast as it wears 
away, it is renewed from beneath. This seemingly simple pro- 
cess is very important, for by it a uniform thickness is secured 
to the covering of the body. If it were otherwise, this covering 
would grow thicker as it grew older, like the bark of a tree, 
until it became unwieldly ; it would prevent perspiration also, 
and this, as we shall see, would be fatal to life. The growth of 
the true skin is provided for in the blood vessels which abound 
in it. 

6. The Nails. — These are appendages of the skin. The nail 
grows from a fold of the cuticle at the root, and from the under 
surface. The rapidity of its growth can be ascertained by filing 
a slight groove on its surface, and noticing how the space be- 



THE INTEGUMENT. 



33 



tween it and the root of the hail increases, in the course of a 
few weeks. When the nail is removed by any accident, it will 
be replaced by a new one, if the root be not injured. The 
practice of biting the nails should be avoided, not only because 
of the ugly shape which is produced, but because it impairs the 
sense of touch in the ends of the fingers. The nail serves as a 
protection to the end of the finger, and also enables us to grasp 
more firmly, and to pick up small objects. 

7. The Hair — The hair is 
produced in a similar manner, 
the skin forming depressions, 
or hair sacs, from the bottom 
of which they grow and are 
nourished (Fig. 7). The bulb, 
or root, from which the hair Q 
arises, is lodged in a small 
pouch, or depression in the 
skin. The shaft is the part 
which grows out beyond the 
level of the skin. Its growth 
is altogether in one direction, 
in length alone. 

8. The outer part of the 
hair is quite firm, while its 
interior is softer, and sup- 
pHes the nutriment by which it grows. The hair is a protec- 
tion to the parts it covers. On the head, it shields the brain 
from extremes of heat and cold, and moderates the force of 
blows upon the scalp. On the body it is useful in afi'ording a 
more extensive surface for carrying off the perspiration. 

9. The Complexion. — In the deeper cells of the scarf-skin 
lies a pigment, or coloring matter, consisting of minute colored 
grains. On this pigment complexion depends ; and its presence, 
in less or greater amount, occasions the difference of hue that 
exists between the light and the dark races of men, and between 




Fig. 7.— a. b. The Root of a Haib. 

2, 3. The skin forming the hair sac. 4. 

baceous glands. 5. The hair sac. 

c. Transverse Section of a Hair. 



Se- 



34 THE INTEGUMENT. 

the blonde and brunette of the white races. Freckles are due 
to an irregular increase of coloring matter. 

10. The Sebaceous Glands. — In all parts of the surface 
where the hairs grow are to be found the sebaceous, or oil-pro- 
ducing, glands. These glands are little rounded sacs, or pouches, 
usually connected with the hair-bulbs; and upon these bulbs 
they empty their product of oil, which acts as a natural dressing 
for the hair (4, Fig. 7). A portion of the sebaceous matter passes 
out upon the surface, and prevents the cuticle from becoming 
dry and hard. It also sheathes the skin from the irritation by 
the acrid properties of the perspiration. The glands situated 
upon the face and forehead, open directly upon the skin. In 
these, the sebaceous matter is liable to collect, and become too 
hard to flow off naturally. The mouths of these glands, 
around the nose and on the forehead of young people, frequently 
appear as small black points, which are incorrectly called 
"worms." 

11. The Pepspipatory Glands. — The chief product of the skin's 
action is the perspiration. For the formation of this, there are 
furnished countless numbers of little sweat-glands in the true 
skin. They consist of fine tubes which measure about one- 
tenth of an inch in length. In diameter, they are about one 
three-hundredth of an inch, and upon parts of the body there 
are not far from three thousand of these glands to the square 
inch. Their whole number in the body is, therefore, very 
great ; and it is computed if they were all united, end to end, 
their combined measurement would exceed three miles. 

12. The Sensible and Insensible Pepsplpatlon. — The pores 
of the skin are constantly exhaling a watery fluid; but, 
under ordinary circumstances, there is no moisture apparent 
upon the surface, for it passes off" in the form of vapor as rapidly 
as it is formed. This is called insensible perspiration. Under 
the influence of heat or exercise, however, this fluid is formed 
more abundantly and appears on the surface in minute, color- 
less drops. It is then termed sensible perspiration, Water, is 



THE INTEGUMENT. 35 

the chief part of this fluid. The average daily amount escaping 
from the body by perspiration in the adult, is not far from 
two pints, or more than nine grains each minute. 

13. The Uses of the Perspipation. — Besides liberating from 
the blood this large amount of water, with the worn-out matter 
it contains, perspiration regulates the temperature of the body. 
As evaporation always diminishes temperature, so perspiration 
as it passes off" in the form of fine vapor .cools the surface. In 
hot weather this function is much more active, and the cooling 
influence increases in proportion. 

14. The importance of perspiration is shown by the effects 
that often follow its temporary interruption, namely, headache, 
fever, and the other symptoms that accompany "taking cold." 
AVhen its flow is stopped for a considerable time, the conse- 
quences are very serious. Experiments have been performed 
upon certain smaller animals, as rabbits, to ascertain the results 
of closing the pores of the skin. When they are covered by a 
coating of varnish impervious to water and gases, death ensues 
in from six to twelve hours; the attendant symptoms resem- 
bling those of suffocation. 

15. The Importance of Bathing. — Erom these considera- 
tions, it is evident that health must greatly depend upon keep- 
ing the skin clean. " He who keeps the skin ruddy and soft, 
shuts many gates against disease." For as the watery portion 
of the perspiration evaporates, the solid matter is left behind. 
There, also, remain the scales of the dead scarf-skin and the 
excess of sebaceous matter. The healthful action of the skin 
requires that these impurities be removed by the frequent appli- 
cation of water. 

16. In warm climates and during hot weather, bathing is 
especially necessary. For a person in good health, a daily cold 
bath is advisable. To this should be added occasionally a tepid 
bath, with soap, water alone not being sufficient to remove im- 
purities of a greasy nature like the sebaceous matter. 

17. There is a maxim by the chemist Liebig, to the effect 



36 THE INTEGUMENT. 

that the civilization of a nation is high in proportion to the 
amount of soap that it consumes ; and that it is low in propor- 
tion to its use of perfumes. In some degree, we may apply the 
same test to the refinement of an individual. The soap removes 
impurity ; the perfume covers, while retaining it. 

18. The different kinds of Baths. — All persons are not 
alike able to use the cold bath. When the health is vigorous, a 
prompt reaction and glow upon the surface will show that it is 
beneficial. Where this pleasurable feeling is not experienced, 
but rather a chill and sense of weakness follows, we are warned 
that the system will not endure cold bathing. 

19. It should also be borne in mind, that the warm or hot 
bath cannot be continued so long, or repeated so frequently as 
the cold, on account of the weakening effect of unusual heat so 
applied to the body. For persons who are not in robust health, 
one warm bath each week is sufficient. Sea-bathing is even 
more invigorating than fresh-water bathing. Those who cannot 
endure the fresh water, are often benefited by the salt-water 
baths. 

20. Time and Manner of Bathing. — A person in sound 
health may take a bath at almost any time, except directly after 
a full meal. The most appropriate time is about three hours 
after a meal, the noon-hour being probably the best. For the 
cold bath, taken rapidly, no time is better than immediately 
after rising. Those beginning the use of cold baths should first 
try them at 70° Fahr., and gradually use those of a lower tem- 
perature. From five to twenty minutes may be considered the 
proper limit of time to remain in a bath ; but a sensation of 
chilliness is a signal to withdraw instantly, whether at home, or 
at the sea-side. Two sea-baths may be taken daily ; one of any 
other kind is sufficient. 

21. The body should be warm, rather thaij cold, when step- 
ping into the bath ; and after it, the skin should be thoroughly 
dried with a coarse towel. It is best to continue friction until 
there is a sensation of warmth or "glow" throughout the entire 



THE INTEGUMENT. 37 

surface. This reaction is the test of the good effects of the 
bath. If reaction is still incomplete, a short walk may be 
taken, especially in the sunshine. 

22. Bathing among the Ancients. — The Romans and other 
nations of antiquity made great use of the vapor-bath as a 
means of preserving the health, but more particularly as a 
luxury. The Thermae, as the baths of Rome were called, were 
of great extent, built very substantially, and ornamented at vast 
expense. They were practically free to all, the cost of a bath 
having been less than a cent. It is related that some persona 
bathed seven times a day. After the bath their bodies were 
anointed with perfumed oil. If the weather was fine, they 
passed directly from the Thermae into the gymnasium and 
engaged in some gentle exercise previous to taking the midday 
meal. Swimming was a favorite exercise, and a knowledge of 
it was regarded as necessary to every educated man. Their 
common expression, when speaking of an ignorant person, was, 
"He can neither read nor swim." 

23. The Sun- Bath. — Some also were accustomed daily to 
anoint themselves, and lie or walk in apartments arranged for 
the purpose, with naked bodies exposed to the direct rays of the 
sun. We may judge somewhat of the benefits of the sun, by 
observing the unnatural and undeveloped condition of plants 
and animals which are deprived of light. Plants become 
blanched and tender ; the fish of subterrannean lakes, where the 
light of day does not enter, are undersized, and have no eyes ; 
men growing up in mines are sallow, pale, and deformed. 

24. Clothing. — More harm arises from using too little cloth- 
ing than too much, especially in a changeful climate like 
our own. Boerhaave says, "We should put off our winter 
clothing on midsummer's day, and put it on again the day 
after. Only fools and beggars suffer from the cold ; the lat- 
ter not being able to get sufficient clothes, the others not 
having the sense to wear them." The practice of exposing the 
limbs and necks of young children is quite hazardous. As the 



38 THE INTEGUMENT. 

skin is constantly acting, by night as well as by day, it is 
conducive both to cleanliness and comfort to change the clothing 
entirely on retiring for the night. The day clothing should be 
aired during the night, and the bedding should be aired in the 
morning, for the same reason. 

25. Poisonous Cosmetics. — The extensive use of cosmetics 
for the complexion is a fertile source of disease. The majority 
of these preparations contain certain poisonous mineral sub- 
stances, chiefl}^ lead. The skin rapidly absorbs the fine particles 
of lead, and the system experiences the same evil effects that 
are observed among the operatives in lead-works and painters, 
namely, " painters' colic," and paralysis of the hands, called 
"wrist-drop." 

26. Certain hair-dyes also contain lead, together with other 
noxious and filthy ingredients. These do not work as great 
harm as the cosmetics, since they are purposely kept away from 
the skin, but they rob the hair of its vitality. Eye-washes, too, 
are made from solutions of lead, and many an eye has been 
ruined by their use. They deposit a white metallic scale on 
the surface of the eye, which when in front, permanently blurs 
the sight. 

QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1. What are tlie cliaracteristics of the skin, and what office does it ])erform?. . . 31 

2. What can you state of the structure of the skin ? 31 

3. Describe the cuticle and tell its use 31 

4. Describe the cutis, or true skin, and tell its use 32 

5. Wliat can you state of the nature and gi'owth of the nail ? 32 

6. Of the nature and gro\\i;h of the hair ? 33 

7. Of the offices performed by tiie nails and hair ? 33 

8. How is the ditterence in complexion in different persons accounted for? 33, 34 

9. How is the presence of freckles accounted for ? 34 

10. How does nature provide a dressing for the hair ? 34 

11. What other service do the sebaceous glands perform ? 34 

12. State what you can of the perspiratory glands 34 

13. What is the difference between sensible and insensible perspiration? 34, 35 

14. State the uses and importance of perspiration 35 

15. What impurities gather naturally on the skin ? 35 

16. Repeat what is .said of the imi)ortance of bathing 36, 36 

17. When should we indulge in cold, warm, and sea bathing? 36 

18. What is the effect hi each case ? 36 

I'.t. What directions are given as to the time and manner for bathing ? 36, 37 

20. What is related of bathhig among the ancients ? 37 

21. What are the effects of sun-bathing? 37 

22. What directions are given in relation to clothing the body ? 38 

23. What can you state of poisonous cosmetics ? 38 



CHAPTER IV. 

Food and Drink. 

The Necessity for Food — Waste and Repair — Hunger and 
Thirst — Amount of Food — Renovation of the Body — The 
Sources of Food — Its Classification — Water and its 
Purity — Salt — The Necessity of a Regulated Diet — Milk 
— Meats — Fish — The Vegetables — The Fruits — Coffee 
and Tea. 

1. The Necessity for Food. — Activity is everywhere followed 
by waste. During life, our bodies are ceaselessly active, under- 
going a constant round of changes in nearly all their parts. 
Thus the wear is constant. The particles that are worn out 
are thenceforth useless, and must be removed from the body. 
Their loss must be made good by constantly renewed supplies 
of strength-giving particles. Hence the daily recurring demand 
for food and drink. In health, therefore, while the body is 
always wasting, it is always building up, and does not greatly 
change from day to day either in size, form, or weight. 

2. Hunger and Thirst. — Whien the system is deprived of 
its supply of solid food during a longer time than usual, nature 
gives warning by the sensation of hunger, to repair the losses 
that have taken place. The feeling of thirst, in like manner, is 
evidence that the system is suffering from the want of water. 
The length of time that man can exist without food or drink is 
estimated to be about seven days. If water alone be supplied, 
life will last some days longer ; there being cases recorded where 
men have lived tAventy days and over, without taking any solid 
food. 



40 FOOD AND DRINK. 

3. Quantity of Food. — The quantity of food required varies 
greatly, according to the individual and his mode of life. The 
young, and those who lead active lives, or who live in the open 
air, require more food than the old, the inactive, or the seden- 
tary. Those who live in cold regions require more than the 
inhabitants of hot climates. 

4. The average daily quantity of food and di'ink for a healthy 
man of active habits is estimated at six pounds. This amomit 
may be divided in the following proportions : the mineral king- 
dom furnishes three and one-half pounds, includiQg water and 
salt ; the vegetable kingdom, one and one-half pounds, includ- 
ing bread, vegetables, and fruits ; the animal kingdom, one 
pound, comprising meat, eggs, butter, and the like. This 
amount is about equal to one twenty-fourth part of the weight 
of the body of an adult, — namely, one hundred and forty 
pounds. 

5. Renovation of the Body. — But these pounds of food are 
not all real nutriment. A considerable portion of that which 
we eat is innutritions, and though useful in various ways, is not 
destined to repair the losses of the system. An opinion pre- 
vails that the body is renewed tliroughout once in seven years ; 
how correct this may be it is not easy to decide. Some parts 
change more or less completely several times during the day. 
The muscles, and other parts in frequent use, change often 
durincr a vear ; the bones not so often, and the enamel of tlie 
teeth never changes after being once formed. 

6. The Source of Food. — The tevm food includes all those 
substances, whether liquid or solid, which are necessary for the 
nourishment of the body. The original source of all food is the 
earth, which the poet has fitly styled the " Mother of all liv- 
ing." But the salts of the earth and gases of the air are not all 
directly suited to the wants of man ; for the most part, they 
must be made into forms more closely resembling the tissues of 
liis own body. These higher forms are prepared through the 
medium of the plants and lower animals. 



FOOD AND DRINK. 41 

7. Moreover some of the forms of vegetable and animal life 
are unfit, in their crude state, for man's use, but must pass 
through one or more refining processes. Thus clover, and hay 
and husks of corn, become, through the agency of the bee and 
the cattle, honey, milk and meat. The insect world furnishes 
food for the fowl, and thus indirectly supplies our own tables. 

8. Inorganic Substances. — The substances we use as food 
are classified as organic and inorganic. By organic substances 
are meant those derived from living forms, such as vegetables 
and animals. Inorganic substances are those simpler forms 
which belong to the mineral kingdom. The former alone are 
commonly spoken of as food, but the latter enter very largely 
into the constitution of the body, and must therefore be present 
in our food. With the exception of two articles, water and 
common salt, these substances only enter the system when 
blended with organic substances. 

9. Water. — Water, from a physiological point of view, is 
the most important of all the articles of food. It is everywhere 
found in the body, even in the bones and the teeth. It is esti- 
mated that two-thirds of the body is water. The teeth, the 
densest of the solids in the human system, contain ten per cent, 
of water. The muscles, tendons, and ligaments are more than 
half water ; for it is found that they lose more than half their 
weight when dried with moderate heat. But it is in the fluids 
of the body that water is found most abundantly. 

10. Man can remain a longer time without solid food than 
without water. He may be deprived of the former for ten or 
twelve hours without great suffering, but deprivation of water 
for the same length of time will produce both suffering and 
weakness. Water constitutes the great bulk of all our drinks, 
and is also a large constituent of the meats, vegetables, and 
fruits which come upon the table. 

11. Pure Water. — ^It is important that the water we drink 
and use in the preparation of food should be pure. It should 
be clear and colorless, with little or no taste or smell, and free 



42 FOOD AND DRINK. 

from any great amount of foreign ingredients. Chemically pure 
water does not occur in nature ; it is only obtained by the con- 
densation of steam, carefully conducted, and is not as agreeable 
for drinking purposes as the water furnished by springs and 
streams. Rain-water is the purest occurring in nature; but 
even this contains certain impurities, especially the portion 
which falls in the early part of a shower ; for in its descent 
from the clouds, the particles floating in the air are caught by 
the falling drops. Water from springs and wells always contains 
more or less foreign matter of mineral origin. This imparts to 
the drink its pleasant taste— the sparkle, or " life," coming 
from the gases absorbed by the water during its passage under 
ground. 

12. Action of Water upon Lead. — The danger of using 
water that has been in contact with certain metals is well 
known. Lead is probably the most poisonous of these sub- 
stances in common use. AVlien pure water and an untarnished 
surface of lead come in contact, the water gradually corrodes 
the metal, and soon holds an appreciable quantity of it in solu- 
tion. \A^ien this takes place the water becomes highly in- 
jurious. 

13. In cities, lead pipes are commonly used to convey water 
through the houses ; lead being also used in the construction of 
roofs, cisterns, and vessels for keeping water and other liquids. 
After the articles of lead have been in use several months, the 
danger of lead-poisoning diminishes. An insoluble coating of 
the sulphate of lead -forms upon the exposed surface, thus pro- 
tecting it from further corrosion. It is, however, a wise precau- 
tion, at all times to reject the water or other fluid that has been 
in contact with leaden vessels over night, or for a number of 
hours. Allow the water in pipes to run freely before using. 

14. Common Salt. — Salt, as an article of food, is obtained 
chiefly from the mineral kingdom ; although plants contain it 
in small quantities, and it is also found in the tissues of nearly 
all animals used as food. Even the water we drink sometimes 



FOOD AND DMNK. 43 

has tmces of it. In the human body, it is an ingredient of all 
the solids and fluids. The importance of salt is shown by the 
value placed upon it in countries where it is rare. On the gold 
coast of Africa, a handful of it will buy one or two slaves ; next 
to gold it is their most valuable commodity. Its necessity to 
animal life is also seen in the great appetite for it among domes- 
tic animals, and also by the periodical resort of herds of wild 
beasts to the " salt-licks" or springs. 

15. Experiments upon domestic animals show that the with- 
drawal of salt from their food, not only makes their hides 
rough and causes the hair to fall out, but also interferes with the 
proper digestion of food. If it be withheld persistently, they be- 
come unable to appropriate nourishment, and die of starvation. 

16. Organic Substances. — The organic food-substances are 
derived from the vegetable and animal kingdoms. They com- 
prise all those articles which are commonly spoken of as " food," 
and are essential to sustain the body in life and strength. They 
are divided into three groups : (1) the Albuminoids, or flesh- 
producers ; among these are albumen, or white of eggs ; caseine 
from cheese ; gluten from wheat ; also the lean part of meat ; 
(2) the Fats or Oils, or the great heat-producers. Among these 
are butter, lard, olive and other vegetable oils. In cold climates, 
the fat of animals is the chief " staff of life," but where vegeta- 
tion is scanty and innutritions, the waters even of the frozen 
regions teem with forms of animal life rich in fat. The Esqui- 
mau consumes daily from ten to fifteen pounds of meat or 
blubber, a large proportion of which is fat. The Laplander 
will drink train-oil, and regards tallow-candles as a great deli- 
cacy. In hot climates, on the other hand, a vegetable fat is 
supplied by the olive and the palm. (3) The Sugars, like the 
last group, are producers of heat. They are, with the exception 
of the sugar of milk and honey, chiefly the products of vegetable 
life ; among the principal sources are the sugar-cane, maple and 
beet-root. Moreover, the sweet-tasting fruits, such as grapes, 
pears, peaches and cherries are rich in grape-sugar. In this group 



44 



FOOD AND DRINK. 




starch is placed, for the reason that it must be changed into 
sugar by digestion, before it can take part in building up the 
body. 

17. The bread stuffs, wheat, com, and rye flours, are more 
than one-half starch. Rice, which is the " staff of life " to one- 
third of the human family, 
contains eighty per cent. Un- 
ripe fruits have much starch 
in them, which renders them 
indigestible when eaten un- 
cooked; for the granules of 
raw starch are but slightly 
acted upon within the body. 
But under the potent chemis- 
try of the sun's ray, this 
crude material is converted 
into sugar. Thus are the 
fruits prepared by the care- 
ful hand of Nature, so that 
when ripe they may be freely used without further preparation. 

18. Necessity of a Regulated Diet. — These three organic 
food-groups are each essential to life. Xeither of them can be 
used to the exclusion of the others without endangering health 
and life. An animal can be starved to death on an unlimited 
allowance of white of egg, or butter, or pure sugar, which repre- 
sent the three classes. But if these are given together, or are 
changed at short intervals, the animals live and thrive. 

19. Milk. — Milk is the earliest nutriment of the human race, 
and from the arrangement of its constituents, may be regarded 
as the model food, no other single article being capable of sus- 
taining life so long. Cow's milk holds casein, one of the albu- 
minoids, about five parts in one hundred ; a fatty principle, 
when separated, known as butter, about four parts ; sugar of 
milk, four parts ; water and salts, eighty-seven parts. The casein 
and fatty substance are far more digestible in milk, than after 



Fig. 



-Granules of Starch. 



FOOD Al^D DRINK. 45 

they have been separated from it in the form of cheese anel 
butter. 

20. The Egg. — The egg contains about two-tliirds water, 
the balance being pure albumen and fat. The fat is in the 
yolk, and gives it its yellow color. Eggs contain none of the 
sugar-principles, and should be eaten with bread or vegetables 
that contain them. Soft-boiled eggs are more wholesome than 
those wliich are hard-boiled or fried, as the latter require longer 
time to digest. 

21. Meats. — The meats, so called, are derived from the 
muscular parts of various animals. They are most important 
articles of food for adults, inasmuch as they are richly stored 
with albuminoid substances, and contain more or less fat. Such 
food is very nourishing and easily digested if eaten when fresh, 
— veal and pork being exceptions. The flesh of young animals 
is more tender and, in general, more digestible than that of 
older ones. All meat is more tough immediately after the kill- 
ing of the animal, but improves by being kept a certain length 
of time. 

22. Cold is one means of preserving meat from decay. In 
the markets of northern Russia, the frozen carcases of animals 
stand exposed for sale in the winter air for a considerable time, 
and are sawn in pieces, like sticks of wood, as the purchases are 
made; such meat, when thawed, being entirely fit for food. 
Beef and pork are preserved by salting down in brine, and in 
this condition may be carried on long voyages or kept for future 
use. Salted meat is not as nutritious as fresh, since the brine 
absorbs its rich juices and hardens its fibres. 

23. Cooking. — The preparation of food by the agency of 
fire is of almost universal practice, even among the rudest 
nations. The object of cooking is to render food more easy of. 
digestion by softening it, to develop its flavor, and to raise its 
temperature more nearly to that of the body. A few articles of 
flesh-food are eaten uncooked in civilized lands, the oyster being 
an instance. Raw meat is occasionally eaten by invalids with 



46 FOOD AND DRIXK. 

weak digestive powers, and by men training for atliletic con- 
tests. 

24. In boiling meat, the water in which it is placed tends to 
dissolve its nutrient juices. In fact, the cooking may be so 
conducted as to rob the meat of its nourishment, its tenderness, 
and even of its flavor. The proper method, in order to preserve 
these qualities, is to place the meat in boiling water, which, 
after a few minutes, should be reduced in temperature. In this 
way the intense heat, at first, hardens the exterior layers and 
imprisons the delicate juices ; after that, moderate heat best 
softens it throughout. When soup is to be made, an opposite 
course should be pursued ; for then the object is to extract the 
juices and reject the fibre. Meat, for such purpose, should be 
cut in small pieces and put into cold water, which should then 
be gradually raised to boiling heat. 

25. Boasting is probably the best method of cooking meat, 
especially "joints" or large pieces, as by this process the meat 
is cooked in its own juices. Eoasting should begin with in- 
tense heat, and be continued at a moderate temperature, in 
order to prevent the drying out of the nutritious juices, as by 
this process an outer coating or crust of coagulated albumen is 
formed. During tliis process the meat loses one-fourth of its 
weight, but the loss is almost wholly water, evaporated by the 
heat. Too intense or prolonged heat will dry the meat, or burn 
it. Frying is the worst possible method, as the heated fat, by 
penetrating the meat, or other article placed in it, dries and 
hardens it, and thus renders it indigestible. 

26. Trichina. — It should be remembered that ham, sausages, 
and other forms of pork, should never be eaten in a raw or im- 
perfectly cooked condition. The muscle of the pig is often in- 
fested by a minute animal parasite, or worm, called trieliina 
spiralis. This worm may be introduced alive into the human 
body in pork food, where it multiplies with great rapidity, and 
gives rise to a painful and serious disease. This disease has 
been prevalent in Germany, and cases of it occur from time to 



FOOD AND DRINK. 47 

time in this country. Other varieties of parasites, not less than 
seven in number, may be introduced by means of animal food. 
The true means of preventing them all is thorough cooking. 

27. Fish. — The part of fish that is eaten is the muscle, just 
as in the case of the meats and poultry. It closely resembles 
flesh in its composition, but is more watery. Some varieties 
are very easy of digestion, such as salmon, trout, and cod ; 
others are quite indigestible, especially lobsters, clams, and 
shell-fish generally. 

28. Vegetable Food. — The list of vegetable articles of diet 
is a very long one, including the grains from which our bread- 
stuffs are made, the vegetables from the garden, and the fruits. 
All the products of the vegetable kingdom are not alike useful. 
Some are positively hurtful ; indeed, the most virulent poisons, 
as strychnia and prussic acid, are obtained from certain vege- 
tables. Again, of such articles as have been found good for 
food, some are more nourishing than others : some require very 
little preparation for use, while others are hard and indigestible. 
Great care must therefore be exercised, and many experiments 
made, before we can arrive at a complete knowdedge in reference 
to these articles of diet. Tea, coffee, and other substances from 
w^hich drinks are made, are of vegetable origin. 

29. Bread. — Bread made from wheat-flour has been in use 
for many hundreds of years, and on this account, as well as be- 
cause of its highly nourishing properties, has been aptly called 
" the staff of life." We never become tired of good bread as an 
article of daily food. 

The white kinds of flour contain more starch and less gluten 
than the darker, and are therefore less nutritious. The hard- 
grain wheat yields the best flour. In grinding wheat, the chaff 
or bran is separated by a process called " bolting, " Unbolted 
flour is used for making brown or Graham bread. 

30. The form of bread most easily digested is that which has 
been " leavened," or rendered porous by the use of yeast, or by 
some similar method. Unleavened bread requires much more 



48 FOOD AND DRINK. 

mastication, or chewing. Hot bread is unwholesome, because it 
is not firm enough to be thoroughly masticated, but is converted 
into a pasty, heavy mass that is not easily digested. 

31. Wheaten bread contains nearly every principle requisite 
for sustaining life, except fat. This is commonly added in other 
articles of diet, especially in butter, — " bread and butter," con- 
sequently, forming an almost perfect article of food. The fol- 
lowing experiment is recorded : " A d '^ eating ad libitum of 
white bread, made of pure wheat, an 1 freely supplied with 
water, did not live beyond fifty days. He died at the end of 
that time with all the signs of gradual exhaustion." Death 
took place, not because there Avas anything hurtful in the 
bread, but because of the absence of one or more of the 
food-principles. 

32. The Potato. — The common or Irish potato is the vege- 
table most extensively used in this country and Great Britain. 
Among the poorer classes in Ireland it is the main article of 
food. While it is not so rich in nutritious substances as many 
others, it has some very useful qualities. It keeps well from 
season to season, and men do not weary of its continuous use. 
It is three-fourths water, the balance being chiefly starch. It is 
rich in potash and other salts, and is believed to have been 
highly valuable in warding off the attacks of scurvy wliich re- 
curred in Europe every spring and winter previous to its intro- 
duction. 

33. Fruits. — These are produced, in this country, in great 
abundance, and are remarkable alike for their variety and 
delicious flavor ; consequently they are consumed in large 
quantities, especially during the warmer months. The moderate 
use of ripe fruits, in their season, is beneficial, because they 
offer a pleasant substitute for the more concentrated diet that is 
used in cold weather. Unripe fruits contain starch, which, 
during the process of ripening, is converted into sugar. Such 
fruits are indigestible and should be avoided ; cooking, however, 
in part removes the objections to them. 



FOOD AND DRINK. 49 

34. Coffee. — This is an importaut addition to diet, and if 
moderately used is beneficial to persons of adult age. As com- 
monly employed, it consists of an infusion in boiling water of 
the roasted and ground berry. With most persons its action is 
that of a gentle stimulant, without any injurious reaction. 

35. Another property of coffee is, that it retards the waste 
of the tissues, and consequently permits the performance of 
excessive labor upon an economical and inadequate diet. This 
has been tested among the miners of Belgium. Their allowance 
of solid food was below that found necessary in prisons and 
elsewhere ; but, with the addition of about four pints of coffee 
daily, they were enabled to undergo severe labor without re- 
ducing their muscular strength. The caravans which traverse 
the deserts are supported by coffee during long journeys and 
lengthened privation of food. Among armies it is indispensable 
in supplementing their imperfect rations, and in relieving the 
sense of fatigue after great exposure and long marches. When 
taken with meals, coffee is also thought to promote digestion. 

36. Tea. — The effects of tea are very similar to those of 
coffee, and are due to a peculiar principle called theine. This 
principle is probably the same as that found in coffee, caffeine^ 
since the chemical composition of both is the same. Tea, as 
a beverage, is made from the dried leaves of the plant by the 
addition of hot water ; if the tea is boiled, the oil which gives 
it its agreeable flavor is driven off with the steam. 

37. Chocolate is made from the seeds of the cocoa-tree, a 
native of tropical America. Its effects resemble somewhat those 
of tea and coffee, but it is very rich in nutriment. Linnaeus, 
the botanist, was so fond of this beverage, that he gave to the 
cocoa-tree the name, Theohroma — "the Food of the Gods." 

38. Alcohol. — The word alcohol is of doubtful origin. It is 
commonly supposed to be derived from the Arabic language, 
several words in that tongue resembling it in sound, but none 
of them or any other in the language have a meaning corres- 
ponding with that of the English term. 



50 FOOD AND DRINK. 

39. History. — Alcohol was distilled from rice many centuries 
before that seed was known in Europe. AVe hear of it in 
Bagdad about the year 900. It was known to the Moors of 
Spain, through whom the knowledge of its production spread 
into Western Europe. The first description of alcohol was 
given by a western writer about 1280, who wrote of a " burning 
or ardent water " that resulted from the distillation of wine. It 
may also have been known to the Romans, for Pliny, in the first 
century, wrote of a strong kind of wine that was inflammable — 
a quality that strongly suggests the knowledge of a product of 
distillation. 

40. The Alcohols. — There are at least twelve members of 
the alcohol family, the oldest of which is common alcohol. 
Tliis last is the only one that need be referred to here. Com- 
mon Alcohol is sometimes known as spirit of wine, also as vinic 
alcohol. It is commonly obtained by the distillation of grains 
or of wine. The ardent spirits of commerce (brandy, whiskey, 
gin and rum) contain about one half water, the other half alco- 
hol. Alcohol is also found in all the wines and malt liquors 
(beer, ale, and porter) in varying proportions. The juices of 
ripe, sweet fruits will, at seventy degrees of Fahrenheit, begin 
spontaneously to " work " or ferment ; also wheat and other 
starch-grains, when sprouting, will have their starch changed 
into sugar, and this, in like manner, will undergo fermentation : 
alcohol being one of the results of this action in both cases. 

41. Properties of Alcohol. — Alcohol is a clear, colorless, 
volatile and inflammable liquid of penetrating odor and burning 
taste. It is lighter than water. As it cannot be frozen, it is 
used in thermometers for taking low or exceedingly cold tem- 
peratures. It is also used in spirit levels. It burns with a 
pale, bluish flame, without smoke, and with intense heat ; hence 
its use in the spirit-lamp. 

42. Is Alcohol Food ? — Some authorities class alcohol 
among the food substances. Chemically it is allied to the 
sugars, but the eflfect of alcohol Anthin the body is very unhk^ 



FOOD AND DRINK. 51 

that of the sugars. The latter are nourishing, while the former 
tends to impair nutrition. It was on the mistaken theory that 
alcohol had sustaining power, that for two hundred years the 
armies and navies of certain countries were supplied with 
rations of rum or some other alcoholic drink, under the name of 
"grog." During recent years, a systematic inquiry has been 
made to discover whether the grog-ration was really serviceable 
or the reverse. Tests have been tried upon considerable bodies 
of men, under military discipline, by withdrawing that ration ; 
comparisons have been made at home and abroad, in hot 
climates and in cold, in active service and at rest. The results 
of these observations have without exception been favorable to 
the non-use of spirits. The proportion of ill health, the num- 
ber of sick days, and the incapacity for work have invariably 
been greater among the men to whom the spirit-ration has been 
issued, the quality of food and other circumstances being made 
as nearly equal as possible."^ Hence the conclusion that not only 
is alcohol not a food, but is injurious in itself, and a detriment 
to the food taken.! 



* Alcoliol in tlie Army.— Dr. F. H. Hamilton writes concerning the use of spirits 
by the Amiy of the Potomac in the late war. One gill of whiskey was, for a time, 
given daily to each soldier, on the ground that the hardship and exposure of the 
soldiers demanded it. He condemned the experiment and expressed the hope that 
"no such experiment will ever be repeated in the armies of the United States. My 
conviction is fixed, by the experience and observation of a lifetime, that the regular, 
routine employment of alcoholic stimulants, by a man in health, is never, under any 
circumstances, useful. I make no exeeption in favor of cold, or heat, or rain, nor 
indeed in favor of old drinkers, when we consider them as soldiers." 

+ Beer and "Wine.— Beer and wine are drank chiefly for pleasure or from habit, and 
therefore might be got rid of without any disadvantage ; whilst at the same time they are 
costly, and cause an enormous waste of money amongst the working classes. The cost 
of two pints of ale daily, viz., 3«. Qd. a week, would well clothe a whole family. * * * * 

They do not give strength for work, but on the other hand often make people dull, 
heavy, stupid, and unfit for work. The most severe and continued work can be per- 
formed without them, and there are now some millions of people in this country who 
never taste them. Happy will be the day when they are not drank by any, but particu- 
larly by the working man, who finds it difficult to maintain his family. Tlien will there 
be less quarrelling, poverty, and crime, and more food, clothing, and education. 

About 120 millions of money are spent yearly in these substances, and therefore we 
may well ^sk whether so large a sum is wisely spent. If we allow that there arc 1,000 



52 FOOD AND DRINK. 

43. Does Alcohol Relieve Thirst? -One of the most 
striking properties of alcohol is its affinity for water. When 
swallowed, therefore, its tendency is to deprive the body of 
water and to create thirst rather than to relieve it. It may 
then be stated that alcoholic drinks which appear to quench 
thirst do so by means of the w^ater that, in greater or less 
quantities, dilutes the alcohol they contain. Water, the peer- 
less beverage of nature, does its work better in proportion as it 
remains free from alcohol. For the reason that alcohol seeks 
to draw water to it, the organs of the body that require an 
adequate and ever justly-measured supply of water abhor alco- 
hol. It is found after death from the use of alcoholic drinks, 
that the organs especially sensitive to the hurtful effects of alco- 
hol have become dryer and harder than is natural. 

44. Does Alcohol Enable its Consumers to Resist 
Extreme Cold ? — If this could be proved to be a fact, some of 
its boasted usefulness would receive support. In extremely 
cold climates, the inhabitants are enabled to live comfortably by 
consuming vast quantities of animal food alone, especially if it 
is abundantly oily. AVill alcohol act in a similar w^ay or assist 
in maintaining heat 1 Experience and observation say no. 

45. Before the thermometer was applied to the testing of 
the body's temperature, it was commonly supposed, by reason of 
the sensations of warmth, that alcohol increased bodily heat. 
When, however, this new test was applied, it became apparent 
that those sensations were deceptive, and that there had been 
an actual fall in temperature as the result of imbibing alcohol. 
The surface of the stomach is irritated by this powerful agent, 
causing the nerves of sensation to convey to the brain the 
impression that something has entered the stomach which is 
producing warmth. This is a delusive impression, as Ave know, 
by pouring a few drops of alcohol on the skin, that the 

millions of people in the whole world, and that a 4 lb loaf of bread could be purchased 
everywhere for 6d., that sum would feed the whole world with § lb. of bread daily for 
one month.. — Dr. E. Smith, in ^^ English Magazine," 



FOOD AND DRINK. 53 

tendency is to cool the surface whenever evaporation can take 
place. 

46. The sensation of warmth of the face and surface of the 
body is also deceptive.' The flushing of the face, common to 
hard drinkers, does not indicate that they have a super- 
abundance of animal heat, the temperature of their bodies be- 
ing below normal. The true cause of the flush is a paralysis 
of one set of nerves governing the natural action of the hair-like 
vessels that course just below the skin. Nature has provided 
these infmitely fine vessels with minute controlling nerves, 
whose duty it is to regulate the flow of blood in exposed posi- 
tions. Alcohol paralyzes this control ; the blood flows at ran- 
dom, and the terminal vessels are over-charged with blood. 
Hence the high color which is so remarkable in habitual drinkers 
that it amounts to a disfigurement, is Nature's signal of distress, 
showing that the circulation is deranged and the blood is unduly 
brought into contact Avith the lower temperature of the outer 
air. Alcohol, therefore, is not a producer of heat, but a pro- 
moter of cold, and must be dangerous to any persons taking it 
when they are exposed to low temperatures. 

47. The testimony of those who have had experience in 
contact with the realms of snow and ice is unanimous against 
the cold-resisting property of alcohols. It is recorded of the 
men who served in Napoleon's campaign in Russia, under 
great exposure to cold, that death was hastened by the use of 
alcohol. The evidence of the Monks of St. Bernard is similar. 
Numerous Arctic explorers testify that not only is the temporary 
indulgence liable to result in most serious consequences, but 
that strong, able-bodied men in the habit of using alcoholic 
drinks, are entirely unfitted to resist the cold to which they 
must be exposed. The natives and travelers alike rely upon 
fresh animal food, especially fatty food, and avoid alcohol as a 
danger to life."^ 

* " Alcohol is not the warming cordial and invigorating stimulant tliat it is reputed to 
be, but there is a world-full of preconceived opinions in its fE^vor that must be me* and 



54 FOOD AND DRINK. 

Dr. Kae's Statement.— The Arctic explorer, Dr. Rae, states that he found 
entire avoidance of alcohol necessary, in the far North. The moment a man had 
swallowed a drink of spirits, it was certain that his daj-^s work was nearly at an end. 
" It was absolutely necessary that the rule of total abstinence should be rigidly enforced, 
if we would accomplish our daj-'s task. Any use of liquor, as a beverage, when we had 
work on hand, in that ten'ific cold, was out of the question." 

48. Alcohol Destructive to Life. — Instead of being a pro- 
moter of life, as the early alchemists who produced it hoped it 
would be, alcohol is hostile to life ; it is a poison. Plant life 
is speedily destroyed when brought into close contact mth it. 
The lower animals are poisoned by it. When applied directly 
to small insects and reptiles, death commonly occurs in a few 
seconds or minutes. It is hurtful to the larger animals, and 
the more intelligent of them appear to resent its use instinct- 
ively. This is seen when dogs have been forced to take brandy 
in small doses for some time. Instead of learning to like it, 
they gradually show a gTeater and greater dislike to it.* 

49. The Proper Use of Alcohol. — Like opium, chloral, 
arsenic, and many other poisons, alcohol may be rightly used, 
and that is as a medicine. For the relief of sickness and feeble- 
ness of body or conditions of unusual fatigue alcohol can be 
beneficially used imder the advice of a physician. 



overcome before the true view can make its way. But the truth must prevail at last. 
Its true place is not along with the displays of Avealth and luxuiy upon our sideboards, 
but in the medicine-chest along with hasheesh, henbane, opium, stramonium, and so- 
forth, labeled as a Poison ! "—Dr. A. F. Kinrie. 

* " Tliere is no such thing as a temperate use of spirits. In any quantity they are an 
enemy to the human constitution. Tlieir influence upon the physical organs is unfa- 
vorable to health. They produce weakness, not strength ; sickness, not health ; death, 
not life." — Dr. Alden. 

Adulteration in Liquors.— It is not enough that alcoholic drinks are danger- 
ous when jiurely made, but there is an added danger growing out of the almost uni- 
versal practice of the manufacturers of these drinks to tamper with them and adul- 
terate them with other harmful materials. Xot many months ago the city government 
of Paris caused a testing of all the wines that were brought into the market during 
a month ; there were 1,518 samples of French wine examined and only 65 found 
absolutely free from injurious addition : that is, less than 5 per cent, was really pure.— 
N. Y. Scientific Ti'tnes. 

{For further matter on Alcohol see p. 72.) 



FOOD AND DRINK. 55 

A Mixed Diet affords the best Results.—" Tlie mixed diet to which the 
inclination of a man in temperate climates seems unusually to lead him, when circum- 
stances allow that inclination to develop itself freely, appears to be fully conformable 
to the construction of his dental and digestive apparatus, as well as to his instinctive 
cravings. And whilst on the one hand it may be freely conceded to the advocates of 
' vegetarianism,' that a well-selected vegetable diet is capable of producing, in the 
greatest number of individuals, the highest ^^/li/sicaJ development of which they are 
capable, it may, on tlie other hand, be affirmed with equal certainty, that the substitu- 
tion of a modei-ate proportion of animal flesh is in no way injurious ; but, so far as our 
evidence at present extends, this seems rather to favor the highest mental development. 
And we can scarcely avoid the conclusion that the Creator, by conferring on man a 
remarkable range of choice, intended to qualify him for subsisting on those articles of 
diet, whether animal or vegetable, which he finds most suitable to his tastes and', 
wants." — W. B. Carpenter on the Principles of Physiology. 

Bread.—" The health and power of a nation, as of an army, depend greatly on its: 
food. The quality of bread in any nation, community, or family is a i)retty good 
measure of its civilization. No one can entirely dispense with it. Good or bad, in 
some form it must be had. So it is, and has been from the earliest records of the race, 
and so it will doubtless continue. Leavened or fermented bread is as old as the time 
of Moses, and its value has been fully tested. Whatever be the precise action of the 
leaven, it transforms the grain by partial decomposition of its original elements, and 
leaves as its resultant what all men in all ages have approved. Is the art of making 
good, honest, leavened, Bible bread lost in Massachusetts, as some of our friends 
declare? Baker's bread is almost universally adulterated. Bread hastily made in 
families is mixed in a variety of ways, with a variety of chemicals, and is generally 
imperfectly cooked. Very often the elements of wheat and fat which the body demands 
(a wise and witty clergyman of the last generation used to say, ' bread is the staff of 
life, but bread and butter is a gold-headed cane ') are furnished in underdone pastry, 
made from flour and hog's lard. Any family can have good bread who will take the 
pains. It involves not more than ordinary skill and judgTuent, It ' is to be found on 
the continent of Europe on all the great lines of travel, and is as common among the 
people in France and Germany as it is rare with us.' The materials for a<i honest, whole- 
some loaf are simple and not expensive. The value of time and labor required for 
kneading the dough are the only difficulties, and these we would not undervalue ; 
they are in many families very serious, and not easily overcome."— De?'?^^ on the Food 
of Massachusetts 



56 FOOD AND DRINK. 



QUESTTCNS FOR TOPICAL REVIEW. 

PAGE 

1 How is tlie necessity for food shown ? 39 

5J To what process of waste and repair is the body constantly subjected ? 30 

3. How do you account for the sensations of hunger and thirst ? 30 

4. What further can you state having relation to the subject ? 30 

5. Wlmt can you state in regard to the quantity of food required for the sup- 

port of life ? 40 

6. What further can you state in relation to the process of renovation through 

which the body passes ? ^ 40 

7. Wliat in relation to the selection of articles for food ? 40 

8. "VMiat has been proved as regards animal food ? 41 

0. Of what importance is milk as an article of food ? 41 

10. What are the constituents of milk ? 44, 45 

11. Wliat can you state of eggs as an article of food ? 45 

12. Of the meats, so called, as an article of food ? 45 

13. In what way may beef and pork be preserved ? 45 

14. What can you state of salted meat as food ? 45 

15. What change does meat undergo in the cooking ? 45, 46 

16. What is said for roasting ? 46 

17. What is said about the frying of meats? 46 

IS. State what is said in relation to fish 47 

10. What is stated of the usefulness and other properties of the products of the 

vegetable kingdom ? 47 

20. What further is said of vegetable food ? 47 

21. Why is bread made of wheat floui- so important as an article of food ? 47 

22. Give the statement respecting the potato 48 

23. 'VSTiat is stated of fruits, the use of them, their nutritious qualities, etc.? 48 

24. How general is the existence of perfectly pure water ? 48 

25. What is stated in relation to drinking water ? 48 

26. How does the action of water upon lead affect lead ? 48 

27. What further can you state on the subject ? 48 

28. What properties has coffee as an article of diet ? 48, 49 

29. In what circumstances has coffee been found peculiarly beneficial ? 49 

30. What can you say of the early history of alcohol ? 49 

31. How many members are there of the alcohol family ? What is said of fer- 

mentation ? 50 

32. What are the properties of alcohol ? 50 

.33. Is alcohol a food ? Discuss the subject 50 

34. Does alcohol slake the thirst ? 52 

35. Does alcohol produce heat ? 52 

36. How do you account for the flush observed in the faces of hard drinkers ?. , , 53 

37. Is it safe to drink alcohol when exposed to very cold climates ? 53 

38. Give the effects of alcohol upon lower animals 54 

30. When and how may alcohol be used with safety ? 64 



CHAPTER V. 

Digestion. 

The Principal Processes of Nutrition — The General Plan of 
Digestion — Mastication— The Teeth — Preservation of the 
Teeth — The Action of the Saliva — The Stonnach and the 
Gastric Juice — ^The Movements of the Stomach — Gas- 
tric Digestion — The Intestines — The Bile and Pancrea- 
tic Juice^Intestinal Digestion — Absorption by means of 
Blood-vessels and Lacteals — The Lymphatic or Absor- 
bent System — The Lymph — Conditions which affect Di- 
gestion — The Quality, Quantity, and Temperature of the 
Food — The Influence of Exercise and Sleep. 

1. Nutrition. — The great design of food is to give nutriment 
or nourishment to the body. But this is not accomplished 
directly, as the food must first pass through certain preparatory 
changes, as follows : (1), Digestion, by which the food is re- 
duced to a soluble condition ; (2), Absorption, by which, when 
digested, it is taken up by the blood ; (3), Circulation, which 
carries the enriched blood to the various parts of the system ; 
and (4), Assimilation, by which each tissue selects from the 
blood the materials necessary for its support. By these four 
steps the sustaining power of food is gradually brought into 
exercise, and the vital machinery kept in working order. 

2. General Plan of Digestion. — The great change which 
food undergoes in digestion is essentially a refining process, re- 
ducing articles of diet, which are at first more or less solid, 
crude, and coarse, to a liquid condition, suitable for absorption 
into the blood. The entire process of digestion takes place in 



58 



DIGESTION. 



what is called the "alimentary 
canal," a narrow, crooked tube, 
about thirty feet in its entire 
length. This canal begins in the 
mouth, extends thence downward 
through the gullet to the stomach, 
and thence onward thi^ough the 
small and large intestines. 

3. The stomach and intestines 
are situated in the abdomen (Fig. 
9, C, and Fig. 15), and occupy 
about two-thirds of its space. The 
action to which the food is sub- 
jected in these organs is of two 
kinds — mechanical and chemical. 
By the former it is crushed, agi- 
tated, and carried onward from 
one point to another; by the lat- 
ter it is changed in form through 
the solvent power of the various 
digestive fluids. 

4. Mastication. — As soon as 
solid food is taken into the mouth, 
it undergoes mastication, or chew- 
ing. It is caught between the opposite surfaces of the teeth, 
and by them is cut and crushed into very small fragments. In 
the movements of chewing, the lower jaw plays the chief part ; 
the upper jaw, having almost no motion, acts simply as a point 
of resistance, to meet the action of the former. These move- 
ments of the lower jaw are of three sorts : an up-and-down 
or cutting, a lateral or grinding, and a to-and-fro, or gnawing 
motion. 

5. The teeth are composed of a bone-like material, and are 
held in place by roots running deeply into the jaw. The ex- 
posed portion, or " crown," is protected by a thin layer of 




Fig. 9. — Section of the Trunk 
showing the cavities of the 
Chest and Abdomen. 

A, Cavity of Chest ; B, Diaphragm ; 

C, Abdomen ; D, E, Spinal Column. 



DIGESTION. 



59 




enamel (Fig. 10, a), the hard- 
est substance in the body, 
which, like flint, is capable of 
striking fire with steel. In 
the interior of each tooth is a 
cavity containing blood-ves- 
sels and a nerve, which enter 
it through a minute opening 
at the point of the root (Fig. 
12). 

6. There are two sets of 
teeth : first, those belonging 
to the earlier years of child- 
hood called the milk teeth, 
which are twenty in number 
and small. At six or eight 
years of age,_ when the jaw 
expands, and when the grow- -r. .^ ^ 

^ ' _ o Fig. 10.— Section of a Tooth. 

ing body requires a more a, Enamel ; b, Cavity ; c c, Roots ; d, Body 
p , T , of the Tooth. 

poweriul and numerous set, 

the roots of the milk teeth are absorbed, and the latter are 
"shed," or fall out, one after another (Fig. 11), to make room 
for the permanent set. 

7. There are thirty-two teeth in the permanent set, an equal 
number in each jaw. Each half-jaw has eight teeth, similarly 
shaped and arranged in the same order. The front teeth are 
small, sharp, and chisel-edged, and are well adapted for cutting 
purposes ; hence their name incisors. The canines stand next, 
one on each side of the jaw ; these receive their name from their 
resemblance to the long, pointed tusks of the dog (Fig. 12). 

8. The bicuspids, next in order, are larger and have a broader 
crown than the former ; Avhile beliind them are the molars, the 
largest and most powerful of the entire set. These large back 
teeth, or " grinders," present a broad, rough surface, suital)le for 
holding and crushing the food. 



60 DIGESTION. 

9. It is interesting, at this point, to notice the different 
forms of teeth in different animals, and observe how admirably 
their teeth are suited to the respective kinds of food upon 
which they subsist. In the carnivora, or flesh feedefs, the teeth 
are sharp and pointed, enabling them both to seize their prey, 
and tear it in pieces ; while the herbivora, or vegetable-feeders, 




Fig. 11. — Section of the Jaw. 
1' 2' 3' 4' 5', The Milk Teeth ; 1" to 8", The Germs of the Permanent Set. 

have broad, blunt teeth, with rough crowns, suitable for grind- 
ing the tough grasses and grains upon which they feed. Human 
teeth partake of both forms ; some of them are sharp, and others 
are blunt ; they are therefore Avell adapted for the mastication 
of both flesh and vegetables. Hence we argue that, although 
man may live exclusively upon either vegetable or animal food, 
he shoidd, when possible, choose a diet made up of both 
varieties. 

10. Preservation of the Teeth.— In order that the teeth 



DIGESTION. 



61 



shall remain in a sound and serviceable condition, some care is 
of course requisite. In the first place, they require frequent 
cleansing ; for every time we take food, some particles of it re- 




FiG. 12.— Section of the Jaws— Rtght Side. 
V, A, N, Veins, Arteries, and Nerves of the Teeth. The root of one tooth in each jaw is 
cut vertically to show the cavity and the blood-vessels, etc, within it; 1 to 8, 
Permanent Teeth. 

main in the mouth; and these, on account of the heat and 
moisture present, soon begin to putrefy. This not only renders 
the breath very offensive, but promotes decay of the teeth. 
II. The saliva, or moisture of the uiouth, undergoes a putre- 



62 



DIGESTION. 



factive change, and becomes the fertile soil in which a certain 
minute fungus has its growth. This fluid, too, if allowed to 
dry in the mouth, collects upon the teeth in the form of an 
unsightly, yellow substance, called "tartar." To prevent this 
formation, and to remove other offensive substances, the teeth 
should be frequently cleaned with water, applied by means of a 
soft tooth-brush. 

12. It should be borne in mind that the enamel, Nature's 
protection for the teeth, when once destroyed is never formed 
anew; and the body of the tooth thus exposed, is liable to 
rapid decay. On this account, certain articles are to be guarded 
against ; such as sharply acid substances that corrode the enamel, 
and hard substances that break or scratch it — as gritty tooth 
powders, metal tooth-picks, and the shells of hard nuts. Sud- 
den alternations from heat to cold, when eating or drinking, 
also tend to crack the enamel. 

13. The Action of the Saliva. — A^Tiile the morsel of food 
is cut and ground by the teeth, it is at the same time intimately 
mixed with the saliva, or fluids of the mouth. This constitutes 
the second step of digestion, and is called "insalivation." The 
saliva, the first of the digestive solvents, is a colorless, watery, 
and frothy fluid. It is secreted {i. e. separated from the blood) 
partly by the mucous membrane which lines the mouth; but 

chiefly by the salivary 
glands, of which there 
are three pairs situ- 
ated near the mouth. 

14. These glands con- 
sist of clusters of very 
small pouches, aromid 
which a delicate net- 
work of blood-vessels 
is arranged : they emp- 
ty into the mouth by 

Fig. 13.— Structure of a Salivart Gland. means of little tubeS 





DIGESTION. 63 

or ducts. The flow from these glands is at all times sufficient 
to maintain a soft and moist condition of the tongue and mouth ; 

but when they are excited 
by the presence and taste of 
food, they pour forth the 
saliva more freely. In the 
horse and other animals, 
that feed upon dry and 
coarse fodder, and require 
an abundant supply of saliva, 
we find large salivary glands, 
as well as powerful muscles 
of mastication. 

Fig. 14.— The Head of a Horse, showing the 
large salivary gland (a), its duet {b), the |5. The mingling of the 
muscles of mastication (c, <?, g,/, and g'). •! i ? i 

saliva with the food seems a 
simple process, but it is one that plays an important part in 
digestion. In the first place, it facilitates the motions of masti- 
cation by moistening the food and lubricating the various 
organs of the mouth. Secondly, it prepares the way for other 
digestive acts : by the action of the teeth, the saliva is forced 
into the solid food, softens the harder substances, and assists in 
converting the whole morsel into a semi-solid, pulpy mass, that 
can be easily swallowed, and readily mixed with other digestive 
fluids. The saliva also, by dissolving certain substances, as 
sugar and salt, develops the peculiar taste of each ; whereas, if 
the tongue be dry and coated, they are tasteless. Hence, if 
substances are insoluble, they are devoid of taste. 

16. Finally, the saliva has the property of acting chemically 
upon the food. As we have before stated (Chap. IV.), starch, 
in order to become nutriment, must first be changed to grape 
sugar. This change is, in part, efl'ected by the saliva, and takes 
place almost instantly, whenever it comes in contact with 
cooked starch. This is due to an organic ingredient of the 
saliva called ptyalin. 

17. Importance of Mastication and ln$a|ivation. — Each of 



64 DIGESTION. 

these processes complements the other, and by their joint action, 
they prepare the food in the best possible manner for further 
digestive changes. The study of these preliminary functions 
will appear the more important, when we reflect that they are 
the only ones which we can regulate by the Avill. For, as soon 
as the act of swallowing begins, the food not only passes out of 
sight, but beyond control ; and the subsequent acts of digestion 
are consequently involuntary and unconsciously performed. 

18. It is generally known that rapid eating interferes with 
digestion. How does this occur? In the first place, the flow 
of the saliva is insufficient to moisten the solid parts of the 
food, so that they remain too hard and dry to be easily swallowed. 
This leads to the free and frequent use of water or some other 
beverage, at meals, to " wash down " the food, — a most pernici- 
ous practice. For these fluids, not only cannot take the place 
of the natural digestive juices, but, on the contrary, dilute and 
weaken them. 

19. Secondly, the saliva being largely the medium of the 
sense of taste, the natural flavors of the food are not developed, 
and consequently it appears comparatively insipid. Hence the 
desire for highly-seasoned food, and pungent sauces, that both 
deprave the taste and over excite the digestive organs. Rapid 
eating also permits the entrance of injurious substances which 
may escape detection by the taste, and be unconsciously received 
into the system. In some instances, the most acrid and poison- 
ous substances have frequently been swallowed " by mistake," 
before the sense of taste could act, and demand their rejection. 

20. Thirdly, the food, being imperfectly broken up by the 
teeth, is hurried onward to the stomach, to be by it more 
thoroughly divided. But the stomach is not at all adapted 
to perform the task thus imposed upon it. Hence persons 
who habitually eat too rapidly, frequently fall victims to dys- 
pepsia. Rapid eating also conduces to overeating. The food is 
introduced so rapidly, that the system has not time to recognize 
that its real wants are met, and hence the appetite continues, 



DIGESTION. 



65 



although more nutriment has been swallowed than the system 
requires, or can healthfully appropriate. 

21. The Stomach. — As soon as each separate portion of food 
is masticated and insalivated, it is swallowed ; that is, it is 

caused to move downward 
to the stomach, through 
a narrow muscular tube 
about nine inches in 
length, called the oesoph- 
agus, or gullet (Fig. 
16). The stomach is the 
only large expansion of 
the digestive canal, and 
is a most important or- 
gan of digestion. It is 
a hollow, pear-shaped 
pouch, having a capacity 
of three pints, in the 
adult. 

22. The stomach has 
also two openings ; that 
by which food enters, be- 
ing situated near the 
heart, is called the cardiac, 
or heart orifice ; the other 
is the pylorus, or " gate- 
keeper," which guards the entrance to the intestines, and, under 
ordinary circumstances, permits only such matters to pass it as 
have first been properly acted upon in the stomach. Coins, 
buttons, and the like are, however, readily allowed to pass, be- 
cause they can be of no use if retained. The soft and yielding 
texture of the stomach indicates that it is not designed to crush 
and break-up solid articles of food. 

23. The Gastric Juice. — We have seen how the presence 
of food in the mouth excites the salivary glands, causing the 




Fig. 15.— Section of Chest and Abdomen. 

A, Heart. D, The Liver. 

B, The Lungs. E, Large Intestine. 

C, Stomach. G, Small Intestine. 



66 



DIGESTION. 



saliva quickly to flow. In the same manner, when food reaches 
the stomach, its inner lining, the mucous membrane, is at once 
excited to activity. At first its surface, ' which while the 




Fig. 1G.— The Organs of Digestion. 
O, Esophagus. I, Small Intestines, 

y, Stomach. C, Large Intestines. 

L, Liver. P, Pancreas. 

M, Pylorus. N. Spleen. 

G, Gall-bladder. 

stomach is empty presents a pale pink hue, turns to a bright 
reel color, for the minute blood-vessels which course through it, 
are filled with blood, Presently a clear, colorless, and acid fluid 
flows out, drop by drop, from millions of little tubes, until 
finally the inner surface is moistened in every part, and the 
fluid begins to mingle with the food. This fluid is termed the 
gastric juice, 



DIGESTION. 67 

24. The gastric juice dissolves certain articles of food, espe- 
cially those belonging to the albuminoid class. This solvent 
power is due to its peculiar ingredient, pepsin. The quantity 
of gastric juice secreted daily is very large, probably not less 
than three or four pints at each meal. Though this fluid is 
used in the digestion of the food, it is not lost ; since it is soon 
re-absorbed by the stomach, together with those parts of the 
food which it has digested and holds in solution. 

25. Movements of the Stomach. — The inner coating of 
the stomach is the mucous membrane, which, as we have seen, 
furnishes the gastric juice. Next to this coating lies another, 
called the muscular coat, composed of muscular fibres, some 
of which run circularly, and others in a longitudinal direction. 
These expand to accommodate the food as it is introduced, and 
contract as it passes out. In addition, these fibres are in con- 
tinual motion while food remains in the stomach, and they act 
in such a manner that the contents are gently turned round from 
side to side, or from one end of it to the other. 

26. By these incessant movements of the stomach, the gas- 
tric juice comes in contact with all parts of the food. We are, 
however, not conscious that these movements take place, nor 
have we the power to control them. When such portions of 
the food as are sufficiently digested approach the pylorus, it 
expands to allow them to pass out, and it closes again to con- 
fine the residue for further preparation. 

2?. The knowledge of these and other interesting and in- 
structive facts has been obtained by actual observation; the 
workings of the stomach of a living human being have been 
laid open to view and examined — the result of a remarkable 
accident. Alexis St. Martin, a Canadian voyageur, received a 
gun-shot wound which laid -open his stomach, and which, in 
healing, left a permanent orifice nearly an inch in diameter. 
Through this opening the observer could watch the progress of 
digestion, and experiment with difi'erent articles of food. 

28. Gastric Digestion. — What portions of the food are 



68 DIGESTION. 

digested in the stomach 1 It was formerly thought that all the 
great changes of digestion were wrought here, but later investi- 
gation has taught us better. We now know that the first 
change in digestion takes place in the mouth, in the partial 
conversion of starch into sugar. We also know that, of the 
three organic food principles (considered in Chapter IV.) two — 
the fats and the sugars — are but slightly affected by the stomach ; 
but that its action is confined to that third and very important 
class, from which the flesh is formed, the albuminoids. A few 
articles need no preparation before entering the system, as 
Avater, salt, and fruit-sugar. These are rapidly taken up by the 
blood-vessels of the stomach, which everywhere underlie its 
mucous membrane in an intricate and most delicate network. 
In this way the work of absorption begins. 

29. The albuminoid substances are speedily attacked and 
digested by the gastric juice. From whatever source they are 
derived, vegetable or animal, they are all transformed into the 
same digestive product called alhuminose. This is very soluble 
in water, and is in part absorbed by the blood-vessels of the 
stomach. After a longer or shorter time, varying from one to 
five hours, according to the individual and the quantil;< and 
quality of his food, the stomach will be found empty. ]S"ot 
only the unabsorbed digested food, but also those substances 
which the stomach could not digest, have passed little by little 
through the pylorus, to undergo further action in the intestines. 
At the time of its exit the digested food is of a pulpy consistence, 
and dark color, and is then known as the chyme. 

30. The Intestines. — The intestines are continuous with 
the stomach, and consist of a fleshy tube, or canal, twenty-five 
feet in length. The small intestine, whose diameter is about 
one inch and a half, is twenty feet long and very winding. 
The large intestine is much wider than the former, and five 
feet long (Fig. 23). In the small intestines, the work of diges- 
tion is completed, the large intestine receiving from them the 



DIGESTION. 69 

indigestible residue of the food, and in time expelling it from 
the body. 

31. Intestinal Digestion. — As soon as the food passes the 
pylorus and begins to accumulate in the upper part of the 
intestines, it excites the flow of a new digestive fluid, which 
enters through a small tube, about three inches below the 
stomach. It is formed by the union of two distinct fluids — 
the hile and the ixmcreatic juice. The bile is secreted by the 
liver, the largest gland of the body, and is constantly formed, 
but it flows most rapidly during digestion. During the inter- 
vals of digestion it is stored in the gall-Uadde7\ a small mem- 
branous bag attached to the under side of the liver. This fluid 
is of a greenish-yellow color, having a peculiar smell, and a very 
bitter taste. 

32. The pancreatic juice is the product of a gland called the 
^pancreas, situated behind the stomach. This fluid is colorless, 
viscid, and without odor. By the joint action of these fluids, 
the fatty parts of the food are made ready for absorption. 
There results from this action a white and milky fluid, termed 
the chyle, which holds in solution the digestible portions of the 
food, and is spread over the extensive absorbent surface of the 
small intestines. 

33. The mucous membrane of the intestines, also, produces 
a digestive fluid by means of numerous minute glands ; this is 
called the intestinal juice. From experiments on the loM^er 
animals, it has been ascertained that this fluid exerts a solvent 
influence over each of the three organic food principles, and in 
this way completes the action of the fluids previously mentioned, 
viz. , — of the saliva in converting starch into sugar, of the gastric 
juice in digesting the albuminoids, and of the pancreatic juice 
and bile, in emulsifying the fats. 

34. Absorption. — With the elaboration of the chyle, the 
work of digestion is completed ; but it has not yet become a 
part of the blood, by means of which it is to reach the diff'erent 
parts of the body. The process by which the liquefied food 



70 



DIGESTION. 



passes out of the alimentary canal into the blood is called 
absorption. This is accomplished in two ways ; first, by the 
blood-vessels. We have seen how the inner membrane of the 
stomach is underlaid by a tracery of minute and numerous ves- 
sels, and how some portions of the food are by them absorbed. 
The supply of blood-vessels to the intestines is even greater ; 
particularly to the small intestines, where the work of absorp- 
tion is most carried on. 

35. The absorbing surface of the small intestines, if con- 
sidered as a plane surface, amounts to not less than half a 
square yard. Besides, the mucous membrane is formed in folds 
with an immense number of thread-like prolongations, called 
villi, which indefinitely multiply its absorbing capacity. These 
villi, give the surface the appearance and smoothness of velvet ; 

and during digestion, they 
dip into the canal, and, 
by means of their blood- 
vessels, absorb its fluid 
contents, just 3iSi:liesj)o?igi- 
oles which terminate the 
rootlets of plants, imbibe 
moisture from the sur- 
rounding soil. 

36. Secondly, absorp- 
tion is also effected by 
the ladeals, a set of ves- 
sels peculiar to the small 
intestines. These have 
their beginnings in the 
little villi just mentioned, 
side by side with the 
blood-vessels. These two 
sets of absorbents run in 
different courses, but their destination is the same, which is the 
right side of the heart. The lacteals receive their name from 




Fig. 17.- 
A, Small Intestine 
C, Thoracic Duct, 
E, 



The Lacteals. 
B, Lacteals. 
D, Absorbents. 
Blood-vessel. 



DIGESTION. 71 

their milky- wliite appearance. After a meal containing a portion 
of fat, they are distended with chyle, which they are specially 
adapted to receive. The lacteals all unite to form one tube, the 
tlioracic duct, which passes upward through the thorax, or chest, 
and empties into a large vein, situated just beneath the left col- 
lar-bone. 

37. Circumstances affecting Digestion. — What length of 
time is required for the digestion of food 1 From observations 
made, in the case of St. Martin, the Canadian already referred 
to, it has been ascertained that, at the end of two hours after a 
meal, the stomach is ordinarily empty. How much time is 
needed to complete the digestion of food, within the small in- 
testines, is not certain ; but, from what we have learned respect- 
ing their methods of action, it must be evident that it largely 
depends upon the amount of starch and fat which the food con- 
tains. 

38. In addition to the preparation which the food undergoes 
in cooking, which we have already considered, many circum- 
stances affect the duration of digestion ; such as the quality, 
quantity, and temperature of the food; the condition of the 
mind and body ; sleep, exercise, and habit. Fresh food, except 
new bread and the flesh of animals recently slain, is more 
rapidly digested than that which is stale ; and animal food 
more rapidly than that from the vegetable kingdom. 

39. A wine glassful of ice-water causes the temperature of 
the stomach to fall thirty degrees ; and it requires a half-hour 
before it will recover its natural warmth. A variety of articles, 
if not too large in amount, is more easily disposed of than a 
meal made of a single article ; although a single indigestible 
article may retard the digestion of a meal that without it would 
be easily digested. 

40. Strong emotion, whether of excitement or depression, 
checks digestion, as do also a bad temper, anxiety, business 
cares, and bodily fatigue. The majority of these conditions 
make the mouth dry, that is, tliey restrain the flow of tlu^ saliva; 



72 DIGESTION. 

and without doubt they render the stomach dry also, by pre- 
venting the flow of the gastric juice. And, as a general rule, 
we may decide, from a parched and coated tongue, that the 
condition of the stomach is not very dissimilar, and that it is 
unfit for the performance of digestive dabor. This is one of the 
points which the physician bears in mind when he examines 
the tongue of his patient. 

41. The practice of eating at short intervals, or "between 
meals," as it is called, has its disadvantage, as well as rapid 
eating and over-eating, since it robs the stomach of its needed 
period of entire rest, and thus overtasks its power. With the 
exception of infants and the sick, no persons require food more 
frequently than once in four hours. Severe exercise either 
directly before or directly after eating retards digestion; a 
period of repose is most favorable to the proper action of the 
stomach. The natural inclination to rest after a hearty meal 
may be indulged, but it should not be carried to the extent of 
sleeping ; since in that state the stomach, as well as the brain 
and the muscles, seeks release from labor. 

42. Effect of Alcohol upon Digestion. — "The irritating 
effects of alcohol upon the lining of the stomach are first seen 
in deranged digestive action, in loss of appetite, and at a later 
stage, in changes in the stomach's structure, principally by a 
thickening of the walls of that organ." 

Alcohol and Digestion.— The effects of alcohol upon digestion vary greatly 
according to the quantity imbibed ; it may act as a temporary check, or in large 
doses it may completely arrest the digestive act ; vomiting is frequently induced, 
the stomach thus freeing itself from the hurtful intruder. The habitual use of spirits 
often gives rise to a most distressing form of dyspepsia. 

Dyspepsia due to Alcohol.—" Many cases of dyspepsia are due to alcohol 
solely and wholly, and no reliance whatever can be placed upon the word, statement 
or the assertion under oath of a drunkard ; for 'a drunkard is a liar.' And this holds 
good of both sexes, all ages, everywhere and ever."— D?\ /. M. Fothergill. 

Effect upon the Appetite.— At a Peace Congress hejd at Frankfort, Germany, 
the. inn-keepers found it necessary to increase the price of board of the strangers attend- 
ing the congress, the majority of whom were teetotalers, for the reason that their 
appetites required an amount of solid food in excess of that usually consumed by their 
own nationality, who are habitual drinkers of beer containing appreciable amounts 
of alcohol. 



DIGESTION. 



73 



" Dr. Beaumont was able to observe tlie condition of the 
stomach of Alexis St. Martin (see paragraph 27, page 67) after 
alcoholic excesses. He states that the surface of the organ was 
overcharged with blood, at times drops of blood exuding from 
it ; and that its secretions became thick, unnatural, and slightly 
tinged with blood. It is a fact beyond dispute that other organs 
concerned in the act of digestion, particularly the liver, become 
diseased by the habitual use of spirituous liquors." 

"By direct contact, alcohol acts upon the stomach and leads to a destruction of its 
secreting tubules. Nothing with such certainty impairs the appetite and the digestive 
power as the continued use of strong alcoholic liquids. From tlie stomach it is ab- 
sorbed, and with its distribution through the system it interferes with nutrition and 
leads to a diseased state of the liver, kidneys, and other organs." — Pavy. 

Cordials, Bitters, etc.— In health, alcohol no wise plays a friendly part in 
regard to digestion. And it is just here that a mistake is made by many persons who 
have been deluded into the use of what are termed ' cordials ' ; these are very strong 
alcoholic liquors, and they are supposed by those who use them to be especially appro- 
priate at the end of a hearty meal. Absinthe, the pet poison of the Parisian, is one of 
these falsely-named ' cordial ' substances. These cordials are never less welcome than 
after a substantial meal." So many misleading names have been given to beverages 
(Cordials, Bitters, etc.) that many persons have used them without knowing the evil 
consequences which follow. It is made clear by recent proofs that the so-called cor- 
dials are the most rapidly poisonous of all the spirituous beverages. 

The Digestibility of Solid Foods. — The accompanying table shows some of 
the results obtained from the experiments of Dr. Beaumont upon the stomach of Alexis 
St. Martin. It will surprise many to find that vegetable foods— they are placed in the 
latter part of the table — require, as a rule, as much time for digestion as animal food. 

Time re- 



Food.. 



Mode of 
Cooking. 



Time re- 
quired for 
digestion, 
b. in. 



Pork roasted 5 15 

Cartilage boiled 4 15 

Ducks roasted 4 

Fowls do 4 

Do boiled 4 

Beef fried 4 

Eggs do 3 30 

Do hard boiled. .3 30 

Cheese 3 30 

Oysters stewed 3 30 

Mutton roasted 3 15 

Do boiled 3 

Beef. roasted 3 

Do boiled ^ 45 

Chicken fricasseed .... 2 45 

Lamb broiled 2 30 

Pig (suckling) roasted 2 30 

Goose do 2 30 

Gelatin boiled 2 30 

Turkey do. 2 25 

Eggs. roasted 2 15 

Cod Fish (cured, dry ) . . . boiled 2 

Ox Liver broiled 2 

Venison Steak do 1 30 



p . Mode of qnii-ed for 

Cooking. digestion. 

h. m. 

Salmon Trout boiled 1 30 

Eggs (whipped) raw 1 30 

Tripe (soused) boiled 1 

Pig's Feet (soused) do 1 

Cabbage boiled 4 

Beetroot do 3 45 

Turnips do 3 30 

Potatoes do 3 30 

Wheaten Bread baked 3 30 

Carrot boiled 3 15 

Indian Corn Bread baked , 3 15 

Do. Cake do 3 

Apple-dumpling boiled 3 

Potatoes baked 2 33 

Do roasted 2 30 

Parsnips boiled 2 30 

Sponge Cake baked 2 30 

Beans boiled 2 30 

Apples (sour) raw 2 

Barley boiled 2 

Tapioca do 2 

Sago do 1 45 

Apples (sweet) raw 1 30 

Rice boiled 1 



(For further matter on ALvhol see p. 87.) 



74 DIGESTION. 



QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1. What do you understand by nutrition ? 67 

2. How is the process of nutrition carried on ? 57 

3. Describe the general plan of digestion 57 

4. How is the process of mastication carried on ? 58 

5. State what you can in relation to the formation of the teeth 58 

6. "What, in relation to their arrangement ? 59 

7. What, in relation to the process of "shedding?" 59 

8. In relation to the different forms of teeth in diffei'ent animals ? 60 

9. What causes operate to injure or destroy the teeth ? 61 

10. What suggestions and directions are given for the preservation of the teeth ? 62 

11. What do you understand by insalivation ? 62 

12. How is the process of insalivation carried on ? 63 

13. Of what importance is the saliva to the process ? 63 

14. Of what importance are mastication and insalivation ? 63 

15. Describe the consequences of rapid eating 64 

16. What becomes of the food directly after it has undergone mastication and 

insalivation ? 64 

17. Describe the location and formation of the stomach 65 

18. Describe the process by which the gastric juice is formed 65 

19. What are the properties and uses of the gastric juice ? 65 

20. What are the movements of the stomach, and what their uses ? 67 

21. What further can you state on the subject ? 67 

22. Wliat portions of the food are digested in the stomach ? 68 

23. Describe the location and formation of the stomach ? 68 

24. What furtlier can you state in relation to the stomach ? 68 

25. Describe the process of intestinal digestion 69 

26. What do you understand by absorption ? 69 

27. How is the process of absorption effected ? 70 

28. What are the lacteals, and of what use are they ? 70 

29. What length of time is required for the digestion of food ? 71 

30. What circumstances, of food, affect digestion ? 71 

31. What circumstances, of emotion, aff"ect digestion ? 71 

32. What suggestions and directions are given upon the subject of eating and 

drinking? 72 

33. What is tlie eff'ect of alcohol upon digestion ? 72 

34. How was the effect of alcohol upon the stomach shewn ? 72 




CIRCULATIOX OF THE BLOOD. 

(Heart, Lunijs,Ai*teries i Veins 



CHAPTER VI. 
The Circulation. 

The Blood — Its Plasma and Corpuscles — Coagulation of the 
Blood — The Uses of the Blood — Transfusion — Change 
of Color — The Organs of the Circulation — The Heart, 
Arteries, and Veins — The Cavities and Valves of the Heart 
— Its Vital Energy — Passage of the Blood through the 
Heart — ^The Frequency and Activity of its Movennents — 
The Pulse — The Spygnnograph — The Capillary Blood- 
vessels — The Rate of the Circulation — Assinnilation — 
Injuries to the Blood-vessels 

1. The Blood. — Every living organism of the higher sort, 
whether animal or vegetable, requires for the maintenance of 
life and activity, a circulatory fluid, by which nutriment is 
distributed to all its parts. In plants, this fluid is the sap ; in 
insects, it is a watery and colorless blood; in reptiles and 
fishes, it is red but cold blood ; while in the nobler animals and 
man, it is the red and warm blood. 

2. The blood is the most important, as it is the most abun- 
dant, fluid of the body ; and upon its presence, under certain 
definite conditions, life depends. With the exception of a few 
tissues, such as the hair, the nails, and the cornea of the eye, 
blood everywhere pervades the body, as may be proven by 
puncturing any part with a needle. The total quantity of blood 
in the body is estimated at about one-eighth of its weight, or 
eighteen pounds. 

3. The color of the blood, in man and the higher animals, as 
is well known, is red ; but it varies from a bright scarlet to a 



76 



THE CmCULATIOK'. 



dark purple, according to the part whence it is taken. " Blood 
is thicker than water," as the adage truly states, and has a glu- 
tinous quality. It has a faint odor, resembling that peculiar to 
the animal from which it is taken. 

4. When examined under the microscope, the blood no 
longer appears a simple fluid, and its color is no longer red. It 
is then seen to be made up of two distinct parts : first, a clear, 
colorless fluid, called the plasma ; and secondly, of a multitude 
of minute soHd bodies, or corpuscles, that float in the watery 
plasma. The plasma, or nutritive liquid, is composed of water 
richly charged with materials derived from the food, viz., albu- 
men, which gives it smoothness and swift motion ; fibrin \ cer- 
tain fats ; traces of sugar ; and various salts. 

5. The Blood Corpuscles. — In man, these remarkable 
" little bodies," — for that is the meaning of the word corpuscles 
— are of a yellow color, but by their 
vast numbers impart a red hue to 
the blood. They are very small, 
and if piled one above another, it 
would take at least 14,000 of them 
to stand an inch high. 

6. The corpuscles, just described, 
are known as the red blood-cor- 
puscles. Beside these, and float- 
ing along in the same plasma, are 
the white corpuscles. These are 
fewer in number, but larger and 

globular in form. They are colorless, and their motion is less 
rapid than that of the other variety. The total number of both 
varieties of these little bodies in the blood is enormous. It is 
calculated that in a cubic inch of that fluid there are eighty- 
three millions, and at least five hundred times that number in 
the whole body. 

7. Coagulation. — The blood, in its natural condition in the 
body, remains perfectly fluid; but, within a few minutes after 




The Blood Corpuscles. 



THE CIRCULATION. 77 

its removal from its proper vessels, a change takes place. It 
begins to coagulate, or assume a semi-solid consistence. If 
allowed to stand, after several hours it separates into two dis- 
tinct parts, one of them the coagulum, or clot, which is heavy 
and sinks ; and the other, a clear, straw-colored liquid, called 
serum, which covers the clot. 

8. In this law of coagulation of the blood is our safeguard 
against death by hemorrhage, or loss of blood. If coagulation 
w^ere impossible, the slightest injury in drawing blood would 
prove fatal. Wliereas now, in ordinary small wounds, bleeding 
ceases, because the blood, as it coagulates, stops the mouths of 
the injured blood-vessels. Wlien the larger vessels are cut or 
torn, it is commonly sufficient to close them by a temporary 
pressure ; for in a few minutes the clot will form and seal them 
up. In still more serious cases, where the blood-vessel is of 
large size, the surgeon is obliged to tie a " ligature " about it, 
thereby preventing the force of the blood-current from washing 
away the clots, which, forming within and around the vessel, 
close it effectually. 

9. The Uses of the Blood. — The blood is the great pro- 
vider and purifier of the body. It both carries new materials 
to aU the tissues, and removes the worn out particles of matter. 
This is effected by the plasma. It both conveys oxygen and 
removes carbonic acid. This is done through the corpuscles. 

10. Change of Color. — The blood undergoes a variety of 
changes in its journey through the system. As it visits the 
different organs it both gives out and takes up materials. In 
one place it is enriched, in another it is impoverished. By 
reason of these alterations in its composition, the blood also 
changes its color. In one part of the body it is bright red, or 
arterial ; in another it is dark blue, or venous. In the former 
case it is pure and fit for the support of the tissues ; in the 
latter, it is impure and charged with worn-out materials. (The 
details of the change from dark to bright will be given in the 
chapter on Respiration.) 



78 



THE CIRCULATION. 



II. Circulation. — The blood is in constant motion during life. 
From the heart, as a centre, a current is always setting toward 
the different organs ; and from these organs a current is con- 
stantly returning to the heart. In this way a ceaseless circular 
movement is kept up, which is called the Circulation of the 
Blood. This stream of the vital fluid is confined to certain 
fixed channels, the blood-vessels. Those branching from the 
heart are the arteries ; those converging to it are the veins. 
The true course of the blood was unknown before the beginning 
of the seventeenth century. In 1619 it w^as discovered by the 
illustrious AVilliam Harvey. Like many other great discoverers, 
he suffered persecution and loss, but unlike some of them, he 
was so fortunate as to 
lived long enough to 



see his discovery uni- 
versally accepted, and 
himself honored as a 
benefactor of mankind. 
12. The Heart.— 
The heart is the central 
engine of the circula- 
tion. In this wonder- 
ful little organ, hardly 
larger than a man's fist, 
resides that sleepless 
force by which, during 
the whole of life, the 
current of the blood is 
kept in motion. It is 
placed in the middle 
and front part of the 
chest, inclining to the 
left side. The heart-beat 
may be felt and heard 
between the fifth and 



conquer and survive opposition. He 




Fig. 19.— The Heart a>t) Large Vessels. 
A, Right Ventricle. D, Left Auricle. 



B, Left 

C, Ri"ht Auricle. 



E, Aorta. 

F, Pulmonary Ai'tery. 



THE CIRCULATION. 



79 



sixth ribs, near the breast-bone. The shape of the heart is 
conical, with the point downward and in front. The base, 
which is upward, is attached so as to hokl it securely in its 
place, while the point is freely movable. To avoid friction, 
the heart is enclosed between two layers of serous membrane, 
which forms a kind of sac. This membrane is as smooth as 
satin, and itself secretes a fluid in sufficient quantities to keep 
it at all times well lubricated. The lining membrane of the 
heart, likewise, is extremely delicate and smooth. 

13. The Cavities of the Heart. — The heart is hollow, and 
so partitioned as to contain four chambers or cavities ; two at the 
base, known as the auricles, from a fancied resemblance to the 

ear of a dog, and two 
at the apex or point, 
called ventricles. An 
auricle and a ventricle 
on the same side, com- 
municate . with each 
other, but there is no 
opening from side to 
side. The right side 
always carries the dark 
or venous blood, and 
the left always circu- 
lates the bright or arte- 
rial blood. 

14. If we examine 
the heart, we at once 

Fig. 20.-SECTION of the Heart. notice that though its 

A, Ki6ht Ventricle. E, F, Inlets to the Ventricles, various chambers have 

B, Left " G, Pulmonary Artery. 

c, Right Auricle. H. Aorta. about the Same Capacity, 

D, Left Auricle. ^ "^ ' 

the walls of the ven- 
tricles are thicker and stronger than those of the auricles. This 
is a wise provision, for it is by the powerful action of the for- 
mer that the blood is forced to the most remote regions of the 




80 THE CIRCULATION. 

body. The auricles, on the contrary, need much less power, for 
they simply discharge their contents into the cavities of the 
heart near at hand and below them — into the ventricles. 

15. Action of the Heart. — The substance of the heart is of 
a deep red color, and its fibres reseml^le those of the voluntary 
muscles by which we move our limbs. But the heart's move- 
ments are entirely involuntary. The advantage of this is evi- 
dent ; for if it depended upon us to will each movement, our 
entire attention would be thus engaged, and we would find no 
time for study, pleasure, or even sleep. The action of the heart 
consists in alternate contractions and expansions. During con- 
traction the walls come forcibly together, and thus drive out 
the blood. Then they expand and receive a renewed supply. 
These movements are called systole and diastole. The latter 
may be called the heart's period of repose ; and although it lasts 
only during two-fifths of a heart-beat, or about a third of a 
second, yet during the day it amounts to more than nine hours 
of total rest. 

16. A remarkable property of the tissue of the heart is its 
intense vitality. For while it is more constantly active than 
any other organ of the body, it is the last to part with its vital 
energy. This is especially interesting in view of the fact that 
after life is apparently extinguished, as from dro^^Tiing, or 
poisoning by chloroform, there yet lingers a spark of vitality in 
the heart, which, by continued effort, may be fanned into a 
flame so as to revivify the whole body. 

17. Passage of the Blood through the Heart. — Let us now 
trace the course of the blood through the several cavities of the 
heart. In the first place, the venous blood, rendered dark and 
impure by contact with the changing tissues of the body, returns 
to the right heart by the veins. It enters and fills the right 
auricle during its expansion ; the auricle then contracts and fills 
the right ventricle. Almost instantly, the ventricle contracts 
forcibly and hurries the blood along the great artery of the 
lungs, to be purified in those organs. Secondl}^, having com- 



THE CIRCULATION. 81 

pleted the circuit of the hmgs, the pure and bright arterial 
blood enters the left auricle. This now contracts and fills the 
left ventricle, which cavity, in its turn, contracts and sends the 
blood forth on its journey again through the system. This 
general direction from right to left is the uniform course of 
heart-currents. 

18. The mechanism which compels this' regularity is as simple 
as it is beautiful. Each ventricle has two openings, an inlet 
and an outlet, each of which is guarded by strong curtains, or 
valves. These valves open freely to admit the blood entering 
from the right, but close inflexibly against its return. Thus, 
when the auricle contracts, the inlet valve opens ; but as soon 
as the ventricle begins to contract, it closes promptly. The con- 
tents are then, so to speak, cornered, and have but one avenue 
of escape, that through the outlet valve into the arteries beyond. 
As soon as the ventricle begins to expand again, this valve shuts 
tightly and obstructs the passage. The closing of these valves 
occasions the two heart-sounds, which we hear at the front of 
the chest. 

19. Frequency of the Heart's Action. — The alternation of 
contraction and expansion constitutes the heart-beats. These 
follow each other not only with great regularity, but with great 
rapidity. The average number in an adult man is about seventy- 
two in a minute. Heat, exercise, and food increase its action ; 
cold, fasting, and sleep diminish it. Posture, too, has a curious 
influence ; for if while sitting, the beats of the heart number 
seventy-one, standing erect will increase them to eighty-one, 
and lying down will lower them to sixty-six. 

20. The modifying influence of mental emotions- is very 
powerful. Sudden excitement of feeling will cause the heart 
to palpitate, or throb violentl}^ Depressing emotions some- 
times temporarily interrupt its movements, and the person faints 
in consequence. Extremes of joy, grief, or fear, have occasion- 
ally suspended the heart's action entirely, and thus caused 
death. 



82 THE CIRCULATION. 

21. Again, if we estimate the amount of blood expelled by 
each contraction of the ventricle at four ounces, then the 
weight of the blood moved during one minute will amoimt to 
eighteen pounds ; and in the course of a lifetime, over one 
hundred and fifty thousand tons. These large figures indicate, 
in some measure, the immense labor necessary to carry on the 
interior and vital operations of our bodies. 

22. The Arteries. — The tube-like canals wliich carry the 
blood away from the heart are the arteries. Their walls are 
made of tough, fibrous materials, so that they sustain the mighty 
impulse of the heart, and are not ruptured. In common with 
the heart, the arteries have a delicately smooth lining mem- 
brane. They are also elastic, and thus re-enforce the action of 
the heart : they always remain open when cut across, and after 
death are always found emptied of blood. 

23. The early anatomists observed this condition, and sup- 
posing that the same condition existed during life, came to the 
conclusion that these tubes were designed to act as air-vessels, 
hence the name artery, from Greek words which signif}' " con- 
taining air." This circumstance affords us an illustration of the 
mistaken notions of the ancients in reference to the internal 
operations of the body. Cicero speaks of the arteries as " con- 
ve}dng the breath to all parts of the body." 

24. The arterial system springs from the heart by a single 
trunk, like a minute and hollow tree, ^^ith numberless branches. 
As these branches leave the heart they divide and subdivide, 
continually growing smaller and smaller, until they can no 
longer be traced with the naked eye. If, then, we continue 
the examination by the aid of a microscope, we see these small 
branches sending off still smaller ones, until all the organs of 
the body are penetrated by arteries. 

25. The Pulse. — With each contraction of the left side of 
the heart, the impulse causes a wave-like motion to traverse th© 
entire arterial system. If the arteries were exposed to view, 
we might see successive waves speeding froxri the heart to th<^ 



THE CIRCULATION. 83 

smallest of the branches, in about one-sixth part of a second. 
The general course of the arteries is as far as possible from the 
surface. This arrangement is certainly wise, as it renders 
them less liable to injury, the wounding of an artery being 
especially dangerous. It also protects the arteries from external 
and unequal pressure, by which the force of the heart would be 
counteracted and wasted. Accordingly, we generally find these 
vessels hugging close to the bones, or hiding behind the muscles 
and within the" cavities of the body. 

26. In a few situations, however, the arteries lie near the 
surface ; and if we apply the finger to any of these parts, we 
will distinctly feel a throbbing motion taking place in harmony 
with the heart-beat. This is part of the wave-motion just men- 
tioned, and is known as "the pulse." All are familiar with 
the pulse at the wrist ; but the pulse is not pec\iliar to that 
position, for it may be felt in the neck, at the temple, and else- 
where, especially near the joints. 

27. Since the heart-beat makes the pulse, whatever affects 
the former affects the latter also. Accordingly, the pulse is a 
good index of the state of the health, so far as the health de- 
pends upon the action of the heart. It informs the physician 
of the condition of the circulation in four particulars : its rate, 
regularity, force, and fullness ; and nearly every disease modifies 
in some respect the condition of the pulse. 

28. The Veins. — The vessels by which the blood returns to 
the heart are the veins. At first they are extremely small ; but 
uniting together as they advance, they constantly increase in 
size, reminding us of the way in which the fine rootlets of the 
plant join together to form the large roots, or of the rills and 
rivulets that flow together to form the large streams and rivers. 
In structure, the veins resemble the arteries, but their walls are 
much less elastic. They are more numerous, and communicate 
with each other freely in their course, by means of interlacing 
branches. 

29. But the chief point of the distinction is in the presence 




84 THE CIRCULATION. 

of the valves in the veins. These are little folds of membrane, 
disposed in such a way, that they 
only open to receive blood flowing 
toward the heart, and close against 
a current in the opposite direction. 
Their position in the veins on the 
back of the hand may be readily ob- 
FiG. 21.— The Valves of Served, if we first obstruct the return 
THE Veins. Qf ^Jood by a cord tied around the 

forearm or wrist. In a few minutes the veins will appear 
swollen, and upon them will be seen certain prominences, 
about an inch apart. These latter indicate the location of the 
valves, or, rather, they show that the vessels in front of the 
valves are distended by the blood, which cannot force a passage 
back through them. 

30. This simple experiment proves that the true direction of 
the venous blood is toward the heart. That the color of the 
blood is dark, will be evident, if we compare the hand thus 
bound by a cord with the hand not so bound. It also proves 
that the veins lie near the surface, while the arteries are beneath 
the muscles, well protected from pressure ; and that free com- 
munication exists from one vein to another. If now we test the 
temperature of the constricted member by means of a thermom- 
eter, we win. find that it is colder than natural, although the 
amount of blood is larger than usual. From this fact we infer, 
that Avhatever impedes the venous circulation tends to diminish 
vitality ; and hence, articles of clothing or constrained postures, 
that confine the body or limbs, and hinder the circulation of 
the blood, are to be avoided as injurious to the health. 

31. The Capillaries. — A third set of vessels completes the 
list of the organs of the circulation, namely, the cajnllary vessels, 
so called (from the Latin word cajyiUan's, hair-like), because of 
their extreme fineness. They are, however, smaller than any 
hair, having a diameter of about g-gVo ^^ ^'^^ inch, and can only 
be observed by the use of the microscope. These vessels are 



THE CIRCULATION. 



85 



the connecting link between the last of the arteries and the first 
of the veins. The existence of these vessels was unknown to 
Harvey, and was the one step wanting to complete his great 
discovery. The capillaries were not discovered until 1661, a 
short time after the invention of the microscope. 

32. The circulation of the blood, as seen under the micro- 
scope, in the transparent web of a frog's foot, is a beautiful sight, 
possessing more than ordinary interest from the fact that some- 
thing very similar is taking place in our own bodies on a much 
grander scale. It is like opening a secret page in the history of 
our o^\Ti frames. We there see distinctly the three classes of 
vessels with their moving contents ; first, the artery, with its 
torrent of blood rushing doAvn from the heart, secondly, the 
vein, with its slow, steady stream flowing in the opposite direc- 
tion ; and between them lies the network of capillaries so fine 




Fig. 22.— Web of a Frog's Foot, 
slightly magnified. 



Fig. 23.— Margin of Frog's Web, 
magnifled 30 diameters. 



that the corpuscles can only pass through "in single file." The 
current of the capillaries has an uncertain or swaying motion, 
hurrying first in one direction, then hesitating, and then turning 
back in the opposite direction, and sometimes the capillaries 
contract so as to be entirely empty. Certain of the tissues are 



destitute of capillaries ; such are cartilage 



, hair, and a few others 



86 THE CIRCULATION. 

on the exterior of the body. In all other strnctm-es, networks 
of these vessels are spread out in countless numbers ; so abun- 
dant is the supply, that it is almost impossible to puncture any 
part with the point of a needle Avithout lacerating tens, or even 
hundreds of them. 

33. The capillaries are elastic, and may so expand as to 
produce an effect visible to the naked eye. Let a grain of sand 
lodge in the eye and irritate it, and in a short time the white of 
the eye will be "blood-shot." This appearance is due to an 
increase in the size of these vessels. 

34. Rapidity of the Circulation. — That the blood moves 
with great rapidity is evident from the almost instant effects of 
certain poisons, as prussic acid, which act through the blood.. 
Experiments upon the horse, dog, and other inferior animals, 
have been made to measure its velocity. If a substance, which 
is capable of a distinct chemical reaction (as ]potassium feirocya- 
nide, or harium nitrate), be introduced into a vein on one side of 
a horse, and blood be taken from a distant vein on the other 
side, its presence may be detected at the end of thirty or thirty- 
two seconds. In man, the blood moves with gTeater speed, and 
the circuit is completed in twenty-four seconds. 

35. What length of time is required for all the blood of the 
body to make a complete round of the circulation ] Tliis ques- 
tion cannot be answered with absolute accurac3\ But we lind 
that, under ordinary circumstances, aU the blood makes one com- 
plete rotation every two minutes ; passing successively through 
the heart, the capillaries of the lungs, the arteries, the capillaries 
of the extremities, and through the veins. 

36. Assimilation. — The crowning act of the circulation, the 
furnishing of supplies to the different parts of the body, is 
effected by means of the capillaries. The organs have been 
wasted by use ; the blood has been enriched by the products of 
digestion. Here, within the meshes of the capillary network, 
the needy tissues and the needed nutriment are brought to- 
gether. By some mysterious chemistry, each tissue selects and 



THE CIRCULATION. 87 

withdraws from the blood the materials it requires, and con- 
verts them into a substance like itself. This conversion of life- 
less food into living tissue is called assimilation. The process 
probably takes place at all times, but the period especially 
favorable for it is during sleep. Then the circulation is slower 
and more regular, and most of the functions are at rest. The 
body is then like some trusty ship, which after a long voyage is 
"hauled up for repairs." 

37. Injuries to the Blood-vessels. — It is important that 
every one should be able to discriminate between an artery and 
a vein, in the case of a Avound, and if we remember the physi- 
ology of the circulation it will be impossible to make a mistake. 
For, as we have already seen, hemorrhage from an artery is 
much more dangerous than that from a vein. The latter tends 
to cease spontaneously after a short time. The arterial blood 
flows away from the heart with considerable force, in jets ; its 
color, bright scarlet. The venous blood flows toward the heart 
from that side of the wound furthest from the heart ; its stream 
being continuous and sluggish; its color dark. In an injury to 
an artery, pressure should be made between the heart and the 
Avound ; while in the case of a vein that persistently bleeds, it 
should be made upon the vessel beyond its point of injury. 

38. Effects of Alcohol upon the Heart. — The first symptoms 
after a moderate dose of alcohol is an increase of the heart's 
action, a flushing of the face, a sensation of warmth within, a 
general glow without, and some other appearances, of increased 
vitality. The action has been that of a spur or goad. It has 
caused strength to be expended instead of increasing it, and, in 
fact, costs the system whatever amount of force is necessary to 
expel it ; so that there is a loss of strength, and not a gain. 

39. The late Dr. Parkesmade a careful study of the amount of 
strain put upon the heart by alcohol. He found that it increased 
both the number and force of the heart's pulsations. Tlie 
period of rest between the beats is reduced, and, consequently, 
the heart's nutrition must be interfered with. He estimates, in 



88 THE CIRCULATION. 

one set of experiments, that the extra work of the heart, induced 
by alcohol, was equivalent to the lifting of 15.8 tons one foot 
daily ; and during two days, 24 tons in excess of the regular 
work. 

40. Alcohol as a Fat PpoduoeP. — Alcohol is said to diminish 
waste and to make those " fleshy " who use it. Tliis may well 
be the case in those — and the proportion is not small — who are 
rendered sluggish and sleepy by it. The fat which they acquire 
is the fat of inaction. If we may judge of the true influence 
of alcohol by experiments on the lower animals, that are com- 
pelled to take it pure, we will not gTant it any fattening 
power. 

41. There is a certain "fatty degeneration " in man — the re- 
sult of alcohol-drinking — that is A^ery disastrous, namely a 
deposit of fat in the muscles of the body. This is destructive 
or weakening to muscular power, and when it evinces itself in 
the heart it creates a change that is to be dreaded as sapping 
the strength of the one particular organ that shoidd be strong 
in drinkers. It attacks them at a vital spot. 

42. The blood also undergoes a fatty change which greatly 
impairs its work of nourishing the body. 

The Blood.— "You feel quite sui-e that blood is red, do you not? Well, it is no 
more red than the water of a stream would be if you were to fill it with little red fishes. 
Suppose the fishes to be very, very small, as small as a grain of sand, and closely 
crowded together through the whole depth of the stream, the water would look red, 
woidd it not ? And this is the way in which the blood looks red : only observe one 
thing ; a grain of sand is a mountain in comparison with the little red bodies that float 
in the blood, which we have likened to little fishes. If I were to tell you they meas- 
ured about the 3200th part of an inch in diameter, you would not be much the A^iser ; 
but if I tell you that in a single drop of blood, such as might hang on the point of a 
needle, there are a million of these bodies, you will perceive that they are both very 
minute and very numerous. Not that any one has ever comited them, as j-ou may sup- 
pose, but this is as close an estimate as can be made in view of what is knowu of their 
minute size."— Jlf ace's History of a Mouthful of Bread. 

{For furtlicr matter on Alcohol and Narcotics sec ]). 120.) 



I 



THE CIRCULATION. 89 

TABLE OF THE PRINCIPAL ARTERIES. 

(Seit I'm. i9, OPPOSITE Page 78.) 



The Head« 

Internal Ca-rot'id, 



Supply the brain. 
Ver'te-bral, 

Oph-thal'mic, supplies the eye. 

External Ca-rot'id ( ^^'^^1' supplies the tongue. 
) Fa'ci-al, supplies the lower par 
( Tem'po-ral, supplies the upper part of the head and face. 



aWfiu. ff i Fa'ci-al, supplies the lower part of the face. 



The Trunk, 

The A-or'ta, arising from the heart, is the main arterial trunk. 

Cor'o-na-ry, supplies the walls of the heart. 

Bron'chi-al, supplies the lungs. 

In-ter-cos'tals, supply the walls of the chest. 

G-as'tric, supplies the stomach. 

He-pat'ic, supplies the liver. 

Splen'ic, supplies the spleen. 

Re'nal, supplies the kidney. 

Mes-en-ter'ics, supply the bowels. 

Spi'nal, supplies the spinal cord. 

The Upper Liiiiib. 

Branches of the Ax-il-la'ry, supply the shoulder. 
" " Bra'chi-al, supply the arm. 

" *' Ra'di-al 



supply the forearm and fingers. 
Ul'nar, 



The liOwer Limb. 



Branches of the Fem'o-ral, supply the hip and thigh. 
" " Pop-li-te'al, \ 

" " Tib'i-al, > supply the leg and foot. 

" *' Per-o-ne'al, ) 



90 CIRCULATION. 



QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1 . What can you state of the importance of blood to the body ? 75 

2. Of its great abundance, color, and composition ? 75, 76 

3. Describe the corpuscles of the human blood 73 

4. Wliat is meant by coagulation of the blood ? 76 

5. Wliat wisdom is there in the law of the blood's coagulation ? 77 

C. "Wliat are the two great uses of the blood ? 77 

7. Through what mediums is the blood provided with new material and relieved 

of the old material ? 77 

S. "What changes take place in the color of the blood in its journey through the 

system ? 77 

9. State all you can in relation to the circulation of the blood 78 

10. All, in relation to the size, shape, and location of the heart 78 

11. How is the loss of power in the heart's movements obviated ? , 79. 

12. Give a description of the formation of the heart 79 

13. What can you state of the ventricles and auricles of the heart ? 79 

14. Describe the action of the heart 80 

15. What special vitality does the tissue of the heart possess ? 80 

16. State all you can on the subject SO 

17. Describe the course of the blood through th'e cavities of the heart 80 

18. Describe the mechanism that regulates the heart-currents 81 

19. How do you account for the two heart-sounds at the front of the chest ? 81 

20. State what you can of the frequency of the heart's action 81 

21. Of the activity of the heart 81 

22. What do you understand by the arteries ? 82 

23. State what you can of the arteries and the arterial system 82 

24. What do you understand by the pulse ? 82 

25. In what part of the body may the pulse be felt ? . . 83 

26. What further can you state of the pulse ? 83 

27. Wliat are the veins ? 83 

28. Describe the valves of the veins and their uses 84 

29. Now give a full description of the construction of the veins 84 

SO. What further can you state of the veins ? 84 

31. What do you understand by the capillaries ? 84 

32. What service do the capillaries perform ? 85 

33. Describe the circulation of the blood in the region of the lieart 86 

34. What can you state of the rapidity of the blood's circulation ? 86 

35. Of the process known as assimilation ? 86 

36. Of injuries to the blood-vessels ? 87 

37. What effect does alcohol have upon the heart ? 87 

38. Give the result of Dr., Parke's experiment 87 

39. Wliat can you say of the fat-producing property of ak-oliol ? 88 



CHAPTER VII. 

Respiration. 

The Object of Respiration — The Lungs — The Air-Passages — 
The Movennents of Respiration — Expiration and Inspira- 
tion — The Frequency of Respiration — Capacity of the 
Lungs — The Air we breathe — Changes in the Air fronn 
Respiration — Changes in the Blood — Interchange of 
Gases in the Lungs — Comparison between Arterial and 
Venous Blood — Respiratory Labor — Impurities of the 
Air — Dust — Carbonic Acid — Effects of Impure Air — 
Nature's Provision for Purifying the Air — Ventilation. 

1. The Object of Respiration. — In one set of capillaries, 
or hair-like vessels, the blood is impoverished in order that it 
may support the different members and organs of the body. In 
another capillary system the blood is refreshed and again made 
fit to sustain life. The former belongs to the greater or systemic 
circulation ; the latter to the lesser or pulmonary, the lungs, in 
which organs it is situated. The blood sent from the right side 
of the heart to the lungs is venous, dark, impure, and of a 
nature hurtful to the tissues. But when the blood returns 
from the lungs to the left side of the heart, it has become 
arterial, bright, pure, and no longer injurious. This marvelous 
purifying change is effected by means of the very familiar act of 
respiration, or breathing. 

2. The Lungs. — The lungs are the special organs of respira- 
tion. There are two of them, one on each side of the chest, 
which cavity they, with the heart, almost wholly fill. The 
lung-substance is soft, elastic, and sponge-like. Under pressure 



92 



RESPIRATION. 



of the finger, it crackles, and wlien thrown into water it floats ; 
these properties are due to the presence of air in the minute air- 
cells of the lungs. To facilitate the movements necessary to 
these organs, each of them is provided with a double covering 




Fig. 24.— Organs of the Chest. 



A, Lungs. 

B, Heart. 



D, Pulmonary Artery. 

E, Trachea. 



of an exceedingly smooth and delicate membrane, called the 
pleura. One layer of the pleura is attached to the walls of the 
chest, and the other to the lungs ; and they glide one upon 
the other, with utmost freedom. Like the membrane which 
envelops the heart, the pleura secretes its own lubricating fluid, 
in quantities sufficient to keep it always moist. 

3. The Air-Passages. — The lungs communicate with the ex- 
ternal air by means of certain air-tubes, the longest of which, 
the trachea, or windpipe, runs along the front of the neck 



RESPIRATION. 



93 



(Figs. 24, E, and 25). Witliiii the chest this tube divides into 
two branches, one entering each king ; these in turn give rise to 
numerous branches, or bronchial tubes, as they are called, which 
gradually diminish in size until they are about one-twenty-fifth 
of an inch in diameter. Each of these terminates in a cluster 




25.— Larynx, Trachea, and 
Bronchial Tubes. 




-Diagram and Section of 
THE Air-cells. 



of little pouches, or "air-cells," having very thin walls, and 
covered with a capillary network, the most intricate in the 
body (Fig. 25). 

4. These tubes are somewhat flexible, sufficiently so to bend 
when the parts move in which they are situated ; but they are 
greatly strengthened by bands or rings of cartilage which keep 
the passages always open ; otherwise there would be a con- 
stantly-recurring tendency to collapse after every breath. The 
lung-substance essentially consists of these bronchial tubes and 
terminal air-cells, with the blood-vessels ramifying about them 
(Fig. 26). At the top of the trachea is the larynx, a sort of 
box of cartilage, across which are stretched the vocal cords. 



94 



RESPIRATION. 



Here the voice is produced chiefly by the passage of the respired 
air over these cords, causing them to vibrate. 




Fig. 27.— Section of the Lungs. 

5. Over the opening of the larynx is found the e^piglottis, 
which fits like the lid of a box at the entrance to the lungs, and 
closes during the act of swallowing, so that food and drink shall 
pass backward to the oesophagus, or gullet (Fig. 27). Occasion- 
ally it does not close in time, and some substance intrudes within 
the larynx, when we at once discover, by a choking sensation, 
that " something has gone the wrong way," and, by coughing, 
we attempt to expel the unwelcome intruder. The air-passages 
are lined through nearly their whole extent with mucous mem- 
brane, which keeps them in a constantly moist condition. 

6. The Movements of Respiration. — The act of breathing 
has two parts — (1), inspiration, or drawing air into the lungs, 
and (2), expiration, or forcing it out again. In inspiration, the 
chest extends in its length, breadth, aiid height. The motion 



RESPIRATION. 



95 



outwards and upwards can be observed every time we draw a 
full breath, and is caused by a lifting of the ribs. But the 
motion dow^n wards is not so apparent, as it is caused by a muscle 




Fig. 28.— Section of Mouth and Throat. 

A, The Tongue. C, Vocal Cord. N, Trachea. 

B, The Uvula. B, Epiglottis. O, (Esophagus. 

L, Larynx. 

within the body called the diajpTiragm. This is the thin parti- 
tion which separates the chest from the abdomen, rising like a 
dome within the chest (Fig. 9). With every inspiration, the 
diaphragm contracts, and in so doing, approaches more nearly a 
level surface, and thus enlarges the capacity of the chest. 
Laughing, sobbing, hiccoughing, and sneezing are caused by the 



96 RESPIRATION. 

spasmodic or sudden contraction of the diaphragm. The special 
power of this muscle is important in securing endurance, or 
" long wind," as it is commonly expressed ; which may be ob- 
tained mainly by practice. It is possessed in a marked degree 
by the mountaineer, the oarsman, and the trained singer. As 
the walls of the chest extend, the lungs expand, and the air 
rushes in to fill them. This constitutes an inspiration. The 
habit of taking frequent and deep inspirations, in the erect 
position, with the shoulders thrown back, tends greatly to in- 
crease the capacity and power of the organs of respiration. 

7. Expiration is a less powerful act than inspiration. The 
diaphragm relaxes and ascends in the form of a dome ; the ribs 
descend and contract the chest ; while the lungs themselves, 
being elastic, assist to drive out the air. The latter passes out 
through the same channels by which it entered. At the end of 
each expiration there is a pause, or period of repose, lasting 
about as long as the period of action. 

8. Frequency of Respiration. — It is usually estimated that 
we breathe once during every four beats of the heart, or about 
eighteen times in a minute. "When the action of the heart is 
hurried, a larger amount of blood is sent to the lungs, and, as 
the consequence, they must act more rapidly. Occasionally, 
the heart beats so very forcibly that the lungs cannot keep pace 
with it, and then we experience a peculiar sense of distress from 
the want of air. This takes place when we run until we are 
"out of breath." 

9. Although, as a general rule, the work of respiration goes 
on unconsciously and without exertion on our part, it is never- 
theless under the control of the will. We can increase or 
diminish the frequency of its acts at pleasure, and we can 
"hold the breath," or arrest it altogether for a short time. 
From twenty to thirty seconds is ordinarily the longest period 
in which the breath can be held ; but if we first expel aU the 
impure air from the hmgs, by taking several very deep inspira- 
tions, the time may be extended to one and a half or even two 



KESPIRATION. 97 

minutes. Tliis sliould be remembered, and acted upon, before 
passing through, a burning building, or any place where the air 
is very foul. 

10. The air is not a simple element, as the ancients supposed, 
but is formed by the mingling of two gases, known to the 
chemist as oxygen and nitrogen, in the proportion of one part of 
the former to four parts of the latter. These gases are very 
unlike, beiag almost opposite in their properties : nitrogen is 
weak, inert, and cannot support life ; while oxygen is powerful, 
and incessantly active ; and is the essential element which gives 
to the atmosphere its power to support life and combustion. 
The discovery of this fact was made in 1778 by the French 
chemist, Lavoisier. 

11. Changes in the Air from Respiration. — Air that has 
been once breathed is no longer fit for respiration. An animal 
confined within it will sooner or later die ; so, too, a lighted 
candle placed in it will be at once extinguished. If we collect 
a quantity of expired air and analyze it, we shall find that its 
composition is not the same as that of the inspired air. When 
the air entered the lungs it was rich in oxj^gen ; now it contains 
twenty-five per cent, less of that gas. Its volume, however, 
remains nearly the same ; its loss being replaced by another 
and very different gas, which the lungs exhale, called carbonic 
acid, or, as the chemist terms it, carbon dioxide. 

12. The expired air has also gained moisture. This is 
noticed when we breathe upon a mirror, or the window-pane, 
the surface being tarnished by the condensation of the watery 
vapor given off by the lungs. In cold weather, this causes the 
fine cloud which is seen issuing from the nostrils or mouth with 
each expiration, and contributes in forming the feathery crystals 
of ice which decorate our window-panes on a winter's morning. 

13. Changes in the Blood from Respiration. — The most 
striking change which the blood undergoes by its passage through 
the lungs, is the change of color from a dark blue to bright red. 
That this change is dependent upon respiration has been fully 



98 RESPIRATION. 

proved by experiment. If the trachea, or windpipe, of a living 
animal be so compressed as to exclude the air from the lungs, the 
blood in the arteries will gradually grow darker, until its color is 
the same as that of the venous blood. A^^len the pressure is re- 
moved the blood speedily resumes its bright hue. Again, if an 
animal breathe an atmosphere containing more oxygen than 
atmospheric air, the color changes from scarlet to vermilion, and 
becomes even brighter than arterial blood. This change of 
color is not of itseK a very important matter, but it indicates a 
most important change of composition, 

14. The air, as we have seen, by respiration loses oxygen 
and gains carbonic acid : the blood, on the contrary, gains oxy- 
gen and loses carbonic acid. Oxygen is the food of the blood 
corpuscles ; while the articles we eat and drink go more directly 
to the plasma of the blood. The air, then, it is plain, supplies 
one kind of food, while our articles of diet supply another. But 
there is tliis difference, our lung food is needed constantly, 
while ordinary food is taken at distinct intervals. Again, as 
the demand of the system for food is expressed by the sensation 
of hunger, so the demand for air is marked by a painful sensa- 
tion called suffocation. 

15. Interchange of Gases in the Lungs. — But the air and 
blood do not come in contact — they are separated from each 
other by the walls of the air-cells and of the blood-vessels, — how- 
then do the two gases, oxygen and carbonic acid, exchange 
places ^ Moist animal membranes have a property which en- 
ables them to transmit gases through their substance, although 
they are impervious to liquids. This may be beautifully shown 
by suspending a bladder containing dark venous blood in a jar 
of oxygen. At the end of a few hours the oxygen will have 
diminished, the blood will be scarlet in color, and carbonic acid 
will be found in the jar. 

16. If this interchange takes place outside of the body, it 
must take place much more perfectly within it, where the cir- 
cumstances are of the most favorable character. The walls of 



RESPIRATION. 99 

the vessels and the air-cells are thin and moist, and tlie currents 
of air and blood are in constant motion. Both parts of this 
process of exchange are equally important. Without oxygen 
life ceases ; if carbonic acid is not thrown off, it acts like a 
poison, producing unconsciousness, convulsions, and even death. 
17. Difference between Arterial and Venous Blood. — 
The following table presents the essential points of difference in 
the appearance and composition of the blood, before and after 
its passage through the lungs : 





Venous Blood. 


Abtertal Blood. 


Color, 


Dark blue, 


Scarlet, 


Oxygen, 


8 per cent. , 


18 per cent. 


Carbonic Acid, 


15 to 20 per cent. 


6 per cent, or less. 


Water, 


More, 


Less. 



The temperature of the blood varies considerably; but the 
arterial stream is generally warmer than the venous. The blood 
imparts heat to the air while passing through the lungs, and 
consequently the contents of the right side of the heart have a 
higher temperature than the contents of the left side. 

18. Amount of Respiratory Labor. — During ordinary calm 
respiration, w^e breathe eighteen times in a minute ; and twenty 
cubic inches of air pass in and out of the lungs with every 
breath. From this we calculate that the quantity of air which 
hourly traverses the lungs is about thirteen cubic feet, or 
seventy-eight gallons ; and daily, not less than three hundred 
cubic feet, an amount nearly equal to the contents of sixty 
barrels. 

19. Impurities of the Air. — The oxygen in the atmosphere 
is of such prime importance, and its proportion is so nicely 
adjusted to the wants of man, that any gas or volatile substance 
which supplants it must be regarded as a hurtful impurity. All 
gases, however, are not alike injurious. Some, if inhaled, are 
necessarily fatal; arseniureted hydrogen being one of these, a 
single bubble of which destroyed the life of its discoverer, 
Gelilen. Others are not directly dangerous, but because they 



100 RESPIRATION. 

take the place of oxyge"ii, and exclude it from the lungs, they 
do harm. To this latter class belongs carbonic acid. 

20. Most of the actively poisonous gases have a pungent or 
offensive od®r ; and, as may be inferred, almost all bad smells 
indicate the presence of substances unfit for respiration. Ac- 
cordingly, as we cannot see or taste these impurities, the sense 
of smell is our principal safeguard against them. In this we 
recognize the forethought which has stationed this sense, like a 
sentinel, at the entrance of. the air-passages, to give us warning 
of approaching harm. Take, as an example, the ordinary 
illuminating gas of cities, from which so many accidents happen. 
How many more deaths would occur from it by suffocation and 
explosion, if we were not made aware of leakage by means of 
its disagreeable odor. 

21. " Man's greatest enemy is his own breath," it is said ; but 
chiefly because of the organic matter it contains. Organic mat- 
ter exists in increased measure in the expired breath of sick 
persons, and impart to it, at times, a putrid odor. This is 
especially true in diseases which, like typhiis and scarlet fever, 
are referable to a blood poison. In such cases the breath is one 
of the means by which nature seeks to expel the offending 
material from the system. Hence, those who visit or nurse 
fever-sick persons should obey the oft-repeated direction, " not 
to take the breath of the sick." At such times, if ever, fresh 
air is demanded, and not alone for the sick, but also for those 
who take care of them. 

22. Dust in the Air. — In a lecture on this subject by Pro- 
fessor Tyndall, he remarks that, " by breathing through a cotton 
wool respirator, the noxious air of the sick room is restored to 
practical purity. ' The air thus filtered, attendants may breathe 
unharmed. In all probability, the protection of the lungs wiU 
be the protection of the whole system. For it is exceedingly 
probable that the germs which lodge in the air-passages are those 
which sow epidemic disease in the body. If this be so, then 
disease can certainly be warded off by filters of cotton wool. 



RESPIRATION. 101 

23. Carbonic Acid in the Air. — This gas exists naturally 
in the air in small quantities. In the open air, men seldom 
suffer from carbonic acid, for, as we shall see presently, nature 
provides for its rapid distribution, and even turns it to good 
use. But its ill effects are painfully evident in the abodes of 
men, in which it is liable to collect as the waste product of 
respiration and of that combustion which is necessary for light- 
ing and warming our homes. A man exhales one-half cubic foot 
of carbonic acid per hour ; a single gas-burner liberates five cubic 
feet in the same time, and therefore spoils as much air as ten 
men. A fire burning in a grate or stove emits some impure 
gases, and at the same time abstracts from the air as much 
oxygen as twelve men would consume in the same period, thus 
increasing the relative amount of carbonic acid in the air. From 
furnaces, as ordinarily constructed, this and other gases are con- 
stantly leaking and poisoning the air of tightly-closed apart- 
ments. 

24. Effects of Impure Air. — Carbonic acid, in its pure 
form, is irrespirable, causing rapid death by suffocation. Air 
containing forty parts per thousand of this gas (the composition 
of the expired breath) extinguishes a lighted candle, and is 
fatal to birds ; when containing one hundred parts, it no longer 
yields oxygen to man and other warm-blooded animals ; and is 
of course speedily fatal to them. In smaller quantities, this 
gas causes headache, labored respiration, palpitation, uncon- 
sciousness, and convulsions. 

25. Another unmistakable result of living in and breathing 
foul air is found in certain diseases of the lungs, especially con- 
sumption. For many years the barracks of the British army 
were constructed without any regard to ventilation ; and during 
those years a large number of men died of consumption. At 
last the government began to improve the condition of the 
buildings, giving larger space and air-supply ; and as a conse- 
quence, the mortality from, that disease has diminished more 
than one-third. 



102 RESPIRATION. 

26. The lower animals confined in the impure atmosphere of 
stables and menageries suffer from the same diseases as man. 
Those brought from a tropical climate, and requiring to be 
closely housed, generally die of consumption. In the Zoolog- 
ical gardens of Paris, this disease affected nearly all monkeys, 
until care was taken to introduce fresh air by ventilation ; and 
then it almost wholly disappeared. 

27. Nature's Provision fop Purifying the Air. — We have 
seen that carbonic acid is heavier than air, and is poisonous. 
Why, then, does it not sink upon and overwhelm mankind with 
a silent, unseen wave of death ? Among the gases there is a 
more potent force than gravity, which forever prevents such a 
tragedy. It is known as the diffusive power of gases. It acts 
according to a definite law, and with irresistible force, compelling 
gases, when in contact, to mingle until they are thorouglily 
diffused. The added influence of the winds is usefid, by insur- 
ing more rapid changes in the air ; air in motion being perfectly 
wholesome. The rains also wash the air. 

28. We have seen that the whole animal creation is con- 
stantly taking oxygen from the air, and as constantly adding to 
it vast volumes of a gas hurtful to aU kinds of animals, even in 
small quantities. How, then, does the air retain unchanged its 
life-giving properties ? The uniformly pure state of the air is 
secured by means of the vegetable creation. Carbonic acid is 
the food of the plants, and oxygen is its waste product. The 
leaves are its lungs, and under the . stimulus of sunlight a vege- 
table respiration is set in motion, the effects of which are just 
the reverse of that of animals. Thus nature purifies the air, 
and at the same time builds up two beautiful and useful worlds 
— the life of each growing out of the decay of the other. 

29. Ventilation. — Since the external atmosphere, as provided 
by nature, is always pure, and since the air in our dwellings and 
other buildings is almost always impure, it becomes imperative that 
there should be a free communication from the one to the other. 
This we aim to accomplish by ventilation. As our houses are 



RESPIRATION. 103 

ordinarily constructed, the theory of ventilation, " to make the 
internal as pure as the external air," is seldom carried out. 
Doors, windows, and flues, the natural means of replenishing 
the air, are too often closed against the precious element. 
Special means, or special attention, must therefore be used to 
secure even a fair supply of fresh air. This is still more true 
of those places of public resort, where large numbers of persons 
crowd together. 

30. If there are two openings in a room, one as a vent for 
foul air and the other an inlet for atmospheric air, and if the 
openings be large, in proportion to the number of air consumers, 
the principal object ^^all be attained. Thus, a door and win- 
dow, each opening into the outer air, will ordinarily ventilate a 
small apartment ; or a window alone will answer, if it be open 
both above and below, and the open space at each end be not 
less than one inch for each occupant of the room, when the 
window is about a yard wide. The direction of the current is 
generally from below upward, since the foul, heated air tends to 
rise. Its rate need not be rapid ; a " draught," or perceptible 
current, is never necessary to good ventilation. The tempera- 
ture of the air admitted may be warm or cold. It is thought by 
many that if the air is cold, it is pure ; but this is an error, 
since cold air will receive and retain the same impurities as 
warm air. 

31. Shall we open our bedrooms to the night air 1 Florence 
Nightingale says, in effect, that night air is the only air that we 
can then breathe. " The choice is between pure air without 
and impure air within. Most people prefer the latter, — an un- 
accountable choice. An open window, most nights in the year, 
can hurt no one. In great cities, night air is the best and 
purest to be had in twenty-four hours. I could better under- 
stand, in toAvns, shutting the windows during the day than 
during the night." 

32. Animal Heat. — The temperature of the human body is 
about 100° Falir., and remains about the same througli winter 



104 RESPIRATION. 

and summer, in the tropics as well as in the frozen regions of 
the north. It may change temporarily within the range of 
■about twelve degrees ; but any considerable, or long-continued 
elevation or diminution of the bodily heat is certain to result 
disastrously. 

33. The regulation of the temperature of the body is effected 
by means of perspiration, and by its evaporation. So long as 
the skin acts freely and the air freely absorbs the moisture, the 
heat of the body does not increase, for whenever evaporation 
takes place, it is attended by the abstraction of heat — that is, 
the part becomes relatively colder. This may be tested by 
moistening some part of the surface with cologne, ether, or 
other volatile liquid, and then causing it to evaporate rapidly 
by fanning. The principle that evaporation produces cold has 
been ingeniously and practically employed, in the manufacture 
of ice, by means of freezing machines. 



QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1. What is the object of respiration ? 91 

2. Wliat are the special organs of respiration ? 91 

3. In what organs does a change in the blood take place ? 91 

4. What is the nature of the change ? 91 

5. Wliere are the lungs situated, and what is the character of the substance of 

which they are composed ? 91 

6. Describe the facilities provided for tlie lung movements 92 

7. Describe tlie trachea, or windpipe 92 

8. Describe the bronchial tubes, and their uses 93 

9. What can you state in relation to the epiglottis? 94 

10. Describe the movements necessary to the act of perfect respiration 94 

11. Wliat is the diaphragm, and what is its office ? 95 

12. How may the organs of respiration be so improved as to increase their capa- 

city and power? 96 

13. What is stated in relation to the frequency of respiration ? 96 

14. To what extent may the act of respiration be subjected to our wills ? 96 

15. Wliat is the air, and what are its parts ? 97 

16. What is the character of the air that has been just breathed ? 97 

17. Why is it that such air is not fit for respiration ? 97 

IS. Wliat are the effects, as recorded in notable cases, of confinement in places 

the air of which has been breathed " over and over ?" 97 

19. WHiat can you state of changes in tlie blood from respimtion? 97 

20. Wliatof the air, as an article of food? 98 



RESPIRATION. 105 



PAGE 

21. What, on the subject of interchange of gases in the kings ? 98 

22. Explain the difference between arterial and venous blood 99 

23. Explain, if you can, the cause of the difference •. 99 

24. In relation to the amount of labor exerted in respiration 99 

25. In i-elation to the deleterious properties of diflerent gases 99 

26. What are the properties of carbonic acid gas 100 

27. Describe the effects of carbonic acid gas ? 101 

28. What are the general effects of breathing any impure atmosphere ? 101 

29. What are Nature's provisions for jiurifying the air? 102 

3Q. What hints and directions are given on the subject of ventilation ? 102 

31. How is temperature of the body regulated and sustained ? 104 



CHAPTER VIM. 

The Nervous System. 

Animal and Vegetative Functions — Sensation, Motion, and 
Volition — The Structure of the Nervous System — The 
White and Gray Substances — The Brain — Its Convolu- 
tions — The Cerebellum — The Spinal Cord and its System 
of Nerves — The Anterior and Posterior Roots — The Sym- 
pathetic System of Nerves — The Properties of Nervous 
Tissue — Excitability of Nervous Tissues — The Functions 
of the Spinal Nerves and Cord — The Direction of the 
Fibres of the Cord — Reflex Activity, and its Uses — ^The 
Functions of the Medulla Oblongata and the Cranial 
Ganglia — The Reflex Action of the Brain. 

1. Animal Functions. — The vital processes which we have 
been considering, in the three previous chapters, of digestion, 
circulation, and respiration — belong to the class of functions 
known as vegetative functions. That is, they are common to 
vegetables as well as animals. The plant has its circulatory 
fluid and channels, by which the nutriment is distributed to all 
its parts. It has, also, a curious apparatus in its foliage, by 
which it abstracts from the air those gaseous elements so neces- 
sary to its support ; and thus it accomplishes vegetable respira- 
tion. 

2. The animal, in addition to these vegetative functions, has 
another set of powers, by the use of which he becomes conscious 
of a world external to himself, and brings himself into active 
relations with it. These functions, among which are sensation, 
motion, and volition, not only distinguish the animal from the 



THE NERVOUS SYSTEM. 107 

plant, but, in proportion to their development, elevate one 
creature above another ; and it is by virtue of his pre-eminent 
endowment, in these respects, that man holds his position at 
the head of the animal creation. 

3. Among animals whose structure is very simple, the hydra 
or fresh-water polyp, being an example, no special organs are 
empowered to perform separate functions ; but every part is 
endowed alike, so that if the animal be cut into pieces, each 
portion has all the properties of the entire original ; and, if the 
circumstances be favorable, each of the pieces will soon become 
a complete hydra. As we approach man, in the scale of beings, 
we find that the organs multiply, and the functions become 
more complete. The function of motion, the instruments of 
which — the muscles and bones — have been considered in former 
chapters, and all the other animal functions of man, depend 
upon the set of organs known as the nervous system. 

4. The Nervous System. — The nervous tissue is composed 
of a soft, pulpy substance, which, early in life, is almost fluid, 
but which gradually hardens with the growth of the body. 
^^^len examined under the microscope, it is found to be com- 
posed of two distinct elements : — (1) the white substance, com- 
posing the larger proportion of the nervous organs of the body, 
which is formed of delicate filaments, about -g- Jg-o of an inch in 
diameter, termed the nerve-fibres ; and (2) the gray substance, 
composed of grayish-red, or ashen-colored cells, of various sizes. 

5. The gray, cellular substance constitutes the larger portion 
of those important masses, which bear the name of nervous 
centres and ganglia (from ganglion, a knot), in which all the 
nerve-fibres unite. These white nerve-fibres are found com- 
bined together in long and dense cords, called nerves (from 
neuron, a cord), which serve to connect the nervous centres 
with each other, and to place them in communication with all 
the other parts of the body which have sensibility or power of 
motion. That part of the nervous system which is concerned 
in the animal functions, comprises the brain, the spinal cord. 



lOB THE l^EHVOtfS SYSTEM. 



Fig. 29.— The Cerebro-Spinal System. 



THE NERVOUS SYSTEM. 109 

and the nerves which are derived therefrom ; these, together, are 
called the cerebrospinal system (Fig. 29) ; while that other set 
of organs, which presides over, and regulates the vegetative func- 
tions, is called the sympathetic system of nerves. 

6. The Brain. — The brain is the great volume of nervous 
tissue that is lodged within the skull. It is the largest and most 
complex of the nervous centres, its weight in the adult being 
about fifty ounces, or one-fortieth of that of the whole body. 
The shape of the brain is oval, or egg-shaped, with one extremity 
larger than the other. The brain consists chiefly of two parts : 
the cerehrum, or brain proper, and the cerebellum, or "little 
brain." In addition to these, there are several smaller organs 
at the base, among which is the commencement or expansion of 
the spinal cord, termed the medulla oblongata, or oblong marrow. 

7. The tissue of the brain is soft and easily altered in shape 
by pressure; it therefore requires to be placed in a well-pro- 
tected position, such as is afl'orded by the skull, or cranium, 
which is strong without being cumbrous. In the course of an 
ordinary lifetime, this bony box sustains many blows, with little 
inconvenience ; while, if they fell directly upon the brain, they 
would at once, and completely, disorganize that structure. 
Within the skull, the brain is enveloped by three membranes, 
which at once protect it from friction, and furnish it w4th a 
supply of nutrient vessels. The supply of blood sent to .the 
brain is very liberal, amounting to one-fifth of all that the 
entire body possesses. The brain of man is heavier than that 
of any other animal, except the elephant and whale. 

8. The Cerebrum. — The brain proper, or cerebrum, is the 
largest of the intracranial organs, and occupies the entire upper 
and front portion of the skull. It is almost completely bisected 
by a fissure, or cleft, running through it lengthwise, into two 
equal parts called hemispheres. The exterior of these hemi- 
spheres is gray in color, consisting chiefly of nerve-cells, arranged 
so as to form a layer of gray matter one-fifth of an incli in 
thickness, and is abundantly supplied with blood-vessels. The 



110 



THE NERVOUS SYSTEM. 



interior of the brain, however, is composed ahnost wholly of 
white substance, or nerve-fibres. 

9. The surface of the cerebrum is divided by a considerable 
number of winding and irregular furrows, about an inch deep, 
as shown in Fig. 30. Into these farrows the gray matter of 




Fig. 30. —Upper Surface of the Cerebrum. 

A, Longitudinal Fissure. 

B, The Hemispheres. 

the surface is extended, and, in this manner, its quantity is 
vastly increased. When it is stated that the gray matter is the 
true source of nervous power, it becomes evident that this 
arrangement has an important bearing on the mental capacity 
of the individual. And it is noticed that in children, before 
the mind is brought into vigorous use, these markings or furrows 
on the surface are comparatively shallow and indistinct; the 
same fact is true of the brain in the less civilized races of man- 
kind and in the lower animals. It is also noticeable that, among 



THE NERVOUS SYSTEM. 



Ill 



animals, those are the most capable of being educated which 
have the best development of the cerebrum. 

10. The Cerebellum. — The "little brain" is placed beneath 
the posterior part of the cerebrum, and, like the latter, is divided 
into hemispheres. Like it, also, the surface of the cerebellum 
is composed of gray matter, and its interior is chiefly white 
matter. It is Subdivided by many parallel ridges, which, send- 
ing down gray matter deeply into the white, central portion, 
gives the latter a somewhat branched appearance. This peculiar 
appearance has been called the (uijor vitce, or the " tree of life," 
from the fact that when a section of the organ is made, it bears 
some resemblance to the trunk and branches of a tree (Fig. 31, F). 




Fig. 31.— Vertical Section of the Brain. 
A, Left Hemisphere of Cerebrum. D, The Pons Varolii. 



B, Corpus Callosum. 

C, Optic Thalamus. 



E, Upper Extremity of the Spinal Cord. 

F, The Arbor Vitse. 



In size, this cerebellum, or " little brain," is less than one- 
eighth of the cerebrum. 

II. From the under surface of the cerebrum, and from the 
front margin of the cerebellum, fibres collect together to form 



112 



THE NERVOUS SYSTEM. 



the medulla oblongata (Fig. 32, M a), wliich, on issuing from 
the skuU, enters the spinal column, and then becomes known 
as the spinal cord. From the base of the brain and from the 




Fig. 32.— The Base or the Brain. 



sides of the medulla originate, also, the cranial nerves, of which 
there are twelve pairs. These nerves are round cords of glisten- 
ing white appearance, and, like the arteries, generally lie remote 
from the surface of the body, and are weU protected from 
injury. 

12. The Spinal Cord. — The spinal cord, or "marrow," is a 
cylindrical mass of s^ft nervous tissue, which occupies a cham- 
ber, or tunnel, fashioned for it in the spinal column (Fig. 33). 
It is composed of the same substances as the brain ; but the 
arrangement is exactly reversed, the Mdiite matter encompassing 
or surrounding the gray matter instead of being encompassed by 
it. The amount of the white substance is also greatly in excess 
of the other material. A vertical fissure partly separates the 



THE NERVOUS SYSTEM. 



113 






cord into two lateral halves, and 
each half is composed of two sep- 
arate bundles of fibres, which are 
named the anterior and posterior 
columns. 

13. These columns have entirely 
different uses, and each of them 
unites with a different portion of 
the nerves which have their origin 
in the spinal cord. The importance 
of this part of the nervous system 
is apparent from the extreme care 
taken to protect it from external 
injury. For, while a very slight 
disturbance of its structure suffices 
to disarm it of its power, yet so 
staunch is its bony enclosure, that 
only by very severe injuries is it 
put in peril. 

14. The Spinal Nerves.— The 
spinal nerves, thirty-one pairs in 
number, spring from each side of 
the cord by two roots, an anterior 
and a posterior root. The posterior 
root is distinguished by possessing 
a ganglion of gray matter, and by a 
somewhat larger size. The succes- 
sive points of departure, or the off- 
shooting of these nerves, occur at 
short and nearly regular intervals 
along the course of the spinal cord. 
Soon after leaving these points, 
the anterior and posterior roots 
unite to form the trunk of a nerve, 
which is distributed, by means of branches, to the various 



Fig, 33. 

A, Cerebrum. 

B, Cerebellum. 

D, D, Spinal Cord. 



114 THE NERVOUS SYSTEM. 

organs of that part of the body which this nerve is designed to 
serve. The spinal nerves supply chiefly the muscles of the 
trunk and limbs and the external surface of the body. 

15. The tissue composing the nerves is entirely of the white 
variety, or, in other words, the nerve-fibres ; the same as we 
have observed forming a part of the brain. But the nerves, 
instead of being soft and pulpy, as in the case of the brain, are 
dense in structure, being hardened and strengthened by means 
of a fibrous tissue which surrounds each of these delicate fibres, 
and binds them together in glistening, silvery bundles. Deli- 
cate and minutely fine as are these nerve-fibres, with their 
extremities often only a hair's breadth distant from each other, 
the impression which any one of them communicates is perfectly 
distinct, and is referred to the exact point whence it came. 
This may be illustrated in a simple manner, thus : if two fingers 
be pressed closely together, and the point of a pin be carried 
lightly across from one to the other, the eyes may be closed, 
and yet we can easily note the precise instant when the pin 
passes from one finger to the other. 

16. The Sympathetic System. — The sympathetic system of 
nerves remains to be described. It consists of a double chain 
of ganglia, situated on each side of the spinal column, and 
extending through the cavities of the trunk, and along the neck 
into the head. From these, numerous small nerves are derived, 
which connect the ganglia together, send out branches to the 
cranial and spinal nerves, and form networks in the vicinity of 
the stomach and other large organs. Branches also ascend into 
the head, and supply the muscles of the eye and ear, and other 
organs of sense. 

17. The Properties of Nervous Tissue. — AVe have seen 
that in all parts of this system, there are only two forms of 
nervous tissue ; namely, the gray substance and the white sub- 
stance, so called from their diff'erence of color as seen by the 
naked eye ; or the nerve-cell, and the nerve-fibi'e, so called from 
their microscopic appearance. Now theses ^wo ^issues ai?e not 



THE NERVOUS SYSTEM. 115 

commonly mingled together, but either form separate organs, or 
distinct parts of the same organs. This leads us to the conclu- 
sion that their respective uses are distinct. And this proves to 
be the simple fact ; wherever we find the gray substance, we 
must look upon it as performing an active part in the system, 
that is, it originates nervous impulses ; the white matter, on 
the contrary, is a passive agent, and serves merely as a con- 
ductor of nervous influences. Accordingly, the nervous centres, 
composed so largely of the gray cells, are the great centres of 
power, and the white fibres are simply the instruments by which 
the former communicate with the near and distant regions of 
the body under their control. 

18. The Functions of the Nerves. — The nerves are the 
instruments of the two grand functions of the nervous system. 
Sensation and Motion. If a nerve that has been exposed be 
divided, and the inner end, or that still in connection with the 
nerve-centres, be irritated, sensation is produced, but no move- 
ment takes place. But if the outer end, or that still connected 
with the limb, be irritated, then no pain is felt, but muscular 
contractions are produced. Thus we prove that there are two 
distinct sets of fibres in the nerves ; one of which, the sensory 
fibres, conduct toward the brain, and another, the motor fibres, 
conduct to the muscles. The former may be said to begin in 
the skin and other organs, and end in the brain ; while the 
latter begin in the nervous centres and end in the muscles. 

19. We have already spoken of the two roots of the spinal 
nerves, called, from their points of origin in the spinal cord, the 
anterior and posterior roots. These have been separately cut 
and irritated in the living animal, and it has been found that 
the posterior root contains only sensory fibres, while the anterior 
root has only motor fibres. So that the nerves of a limb may 
be injured in such a way that it will retain power of motion 
and yet lose sensation ; or the reverse condition, feeling with- 
out motion, may exist. Between these two sorts of fibres no 
difference of structure can be found ; and where they have joined 



116 THE NERVOUS SYSTEM. 

to form a nerve it is impossible to distinguish one sort from 
the other. The rate of motion of a message, to or from the 
brain along a nerve, has been metisured by experiment upon 
the lower animals, and estimated in the case of man at about 
two hundred feet per second. As compared with that of elec- 
tricity, this is a very slow rate, but, in respect to the size of the 
human body, it is practically instantaneous. 

20. The Functions of the Spinal Cord. — As the anterior 
and posterior roots of the spinal nerves have separate functions, 
so the anterior and posterior columns of the cord are distinct in 
function. The former are concerned in the production of 
motion, the latter in sensation. 

21. When the spinal cord of an animal has been cut, in 
experiment, it may be irritated in a manner similar to that 
alluded to when considering the nerves. If, then, the upper 
cut surface be excited, it is found that pain, referable to the 
parts below the cut, is produced ; but when the lower cut sur- 
face is irritated, no feeling is manifested. So we conclude that 
in respect to sensation, the spinal cord is not its true centre, 
but that it is merely a conductor, and is therefore the great 
sensory nerve of the body. When the lower surface of the cut 
is irritated, the muscles of the parts below the section are, 
violently contracted. Hence, we conclude that, in respect to 
the movements ordered by the will, the spinal cord is not their 
source ; but that it acts only as a conductor, and is, accordingly, 
the great motor nerve of the body. 

22. Direction of the Fibres of the Cord. — If one lateral 
half of the spinal cord be cut or injured, a very singular fact is 
observed. All voluntary power over the muscles of the corres- 
ponding half of the body is lost, but the sensibility of that side 
remains undiminished. This result shows that the motor fibres 
of the cord pursue a direct course, while its sensory fibres are 
bent from their course. The direction of the anterior or motor 
columns of the cord is downward from the brain. In the 
cord itself, the course of the motor fibres is for the most part a 



THE NERVOUS SYSTEM. 117 

direct one ; but in the medulla oblongata, or upper extremity of 
the cord, and therefore early in their career, these fibres cross 
from side to side in a mass. 

23. From this double interlacing of fibres results a cross 
action between the original and terminal extremity of all nerve- 
fibres which pass through the medulla ; namely, those of all the 
spinal nerves. Consequently, if the right hand be hurt, the 
left side of the brain feels the pain ; and if the left foot move, 
it is the right hemisphere which dictates its movement. 

24. The Reflex Action of the Cord. — We have already 
considered the cord as the great motor and sensory nerve of the 
body, but it has another and extremely important use. By 
virtue of the gray matter, which occupies its central portion, it 
plays the part of an independent nerve centre. The spinal 
cord not oidy conducts some impressions to the brain, but it 
also arrests others ; and, as it is expressed, " reflects " them into 
movements by its own power. This mode of nervous activity 
is denominated the Reflex Action of the cord. A familiar ex- 
ample of this power of the cord is found in the violent move- 
ments which agitate a fowl after its head has been cut off. The 
cold-blooded animals also exhibit reflex movements in an aston- 
ishing degree. A decapitated centipede will run rapidly for- 
ward, and will seemingly strive to overturn, or else climb over 
obstacles placed in its way. 

25. The Uses of the Reflex Action. — The reflex activity of 
the cord is exhibited in the healthy body in many ways, but 
since it is never accompanied with sensation, we do not readily 
recognize it in our own bodies. Eeflex movements are best 
studied in the cases of other persons, when the conditions enable 
us to distinguish between acts that are consciously, and those 
that are unconsciously performed. For example, if the foot of 
a person sound asleep be tickled or pinched, it will be quickly 
withdrawn from the irritation. Again, when a substance like 
melted sealing-wax, or a heated coin, falls upon the hand, the 
limb is snatched away at once, even before the feeling of pain 



118 THE NERVOUS SYSTEM. 

has been recognized by the brain. A^"llen jolted in a rapidly 
moving car, we involuntarily step forward or backward, so as to 
preserve the centre of gravity of the body. 

26. Another variety of reflex motions takes place in certain 
involuntary muscles, and over these the cord exercises supreme 
control. They are principally those niovements which aid the 
performance of digestion and nutrition, the valve-action of the 
pylorus, and other movements of the stomach and intestines. 
In these movements the mind shares no part. And it is well 
that this is so ; for smce the mind is largely occupied with 
affairs external to the body, it acts irregularh^, becomes fatigued, 
and needs frequent rest. The spinal cord, on the contrary, is 
well fitted for the form of work on which depends the growth 
and support of the body, as it acts uniformly, and with a 
macliine-like regularity. 

27. The objects of the reflex activity of the cord are three- 
fold. In the first place, it acts as the protector of man, in his 
imconscious moments. It is his unseen guardian, always ready 
to act, never growing wear}', and never requiring sleep. In the 
second place, it is the regulator of numerous involuntary motions, 
that are necessary to the nutrition of the body. And, thirdly, 
it acts as a substitute and regidates involimtary movements 
in the muscles usually under the influence of the wiU. It 
thus takes the place of the liigher faculties in performing 
habitual acts, and permits them to extend their oj^erations more 
and more beyond the body and its material wants. 

28. The Functions of the Medulla Oblongata. — The pro- 
longation of the spinal cord, Avithin the skull, has been previously 
spoken of as the medulla oblongata. It resembles the cord, in 
being composed of both white and gray matter, and in conduct- 
ing sensory and motor influences. A portion of the medulla 
presides over the important function of respiration, and from it 
arises the pneumogastric nerve, so called because its branches 
serve both the lungs and stomach. The feelings of hunger, 
thirst, and the desire for air are aroused by means of this nerve. 



THE NERVOUS SYSTEM. 119 

29. The Function of the Cerebellum. — The function of 
the cerebellum, or " little brain," is the directing of the move- 
ments of the voluntary muscles. When this organ is the seat 
of disease or injury, it is usually observed that the person is 
unable to execute orderly and regular acts, but moves in a con- 
fused manner as if in a state of intoxication. Like the larger 
brain, or cerebrum, it appears to be devoid of feeling ; but it 
takes no part in the operations of the mind. 

30. The Function of the Cepebrum. — The cerebrum, or 
brain proper, is the seat of the mind ; or, speaking more exactly, 
it is the material instrument by which the mind acts ; and, as 
it occupies the highest position in the body, so it fulfills the 
loftiest uses. All the other organs are subordinate to it : the 
senses are its messengers, which bring it information from the 
outer world, and the organs of motion are its servants, which 
execute its commands. 

3L There have been a few, but only a few, men of distin- 
guished ability whose brains have been comparatively small in 
size ; the rule being that great men possess large brains. The 
relative weight of the brain of man, as compared with the 
weight of the body, does not, in all instances, exceed that of 
the inferior animals ; the canary and other singing-birds have a 
greater relative amount of nervous matter than man ; but man 
surpasses all other creatures in the size of the hemispheres of 
the cerebrum, and in the amount of gray substance which they 
contain. 

32. Impressions conveyed to the hemispheres from the ex- 
ternal world arouse the mental operations called thought, 
emotion, and the will. All these mental acts, and many others, 
are developed through the action of the brain; not that the 
brain and the mind are the same, or that the brain secretes 
memory, imagination, or the ideas of truth and justice, as the 
stomach secretes the gastric juice. But rather, as the nerve 
of the eye, stimulated by the subtile waves of light, occasions 
the notion of color, so the brain, called into action by the 



120 THE NERVOUS SYSTEM. 

mysterious influences of the immaterial soul, gives rise to all tlie 
intellectual, emotional, and voluntary activities of mankind. 

33. Effects of Alcohol upon the Brain.— The brain under 
the influence of small and occasional doses of alcohol shows no 
serious changes other than an increased supply of blood to the 
head. Very serious changes, however, result from the habitual 
use of alcohol ; the brain becomes harder and tougher than is 
natural and its cell elements show a w^asting away, its substance 
appears shrunken, and an undue amount of watery fluid fills the 
cavities in the brain, in order to make up the diminished bulk. 
The blood-vessels of the brain are sometimes found to be in a 
weakened condition and from this various diseased conditions 
may follow. 

34. Effects of Alcohol on the Mind. — Alcohol produces an 
artificial insanity, in which, according to the quantity takeii, 
the various types of mental diseases are distinctly manifest. 
The perceptions are bewildered, there is sleeplessness, loss of 
memory, delusion, clouded reasoning power and benumbed moral 
sense following in the train of alcohol drinking. There is also 
a monomania caused by the prolonged use of alcohol, a craving 
for drink that knows no bounds, and but rarely a cure ; this is 
dipsomania, or thirst madness. 

Trembling- due to Alcohol.— "Another condition is trembling, due to alcohol. 
The hands are shaky, or unsteady, even when at rest, or if the hand is held out it is 
seen to vibrate slightly, or in more advanced condition, ' shakes like an aspen leaf. 
I have seen this in a spirit-drinker, a barber, as almost the only symptom : he worked 
night and day, in shaving, and to ' steady his hand,' partook repeatedly of spirits— at 
first to relieve fatigue and then, because he saw that if he discontinued, his hand was 
too shaky to use the razor. Complete abstinence from alcohol and strong coffee, quite 
removed his tremblings and his desire for spirits."— Zh-. W. S. Greenfield. 

Alcohol a Poison of the Intellect. —" In the normal state of a man's mind, 
all the faculties, the imagination, the judgment, the memory, the association of ideas, 
are regulated by another superior faculty, viz., the attention. Tlie attention of the 
will, is the man himself ; it is the ego which, being in the full possession of the re- 
sources of which it disposes, takes them where it will, when it ^vill, to do whatever it 
pleases. Now in drunkenness, even at the very beginning, the will and the attention 
have disappeared. Nothing is left but the imagination and the memory, which, left to 
themseh-es without regulation and without guides, produce the most irrational results." 
— Charles Richet. 



THE NERVOUS SYSTEM. 121 

"Alcohol ill small doses super-excites certain intellectual faculties— the imagination, 
the memory and the association of ideas, but it paralyzes others, specially the will, 
the reflection and judgment. Yet, with a stronger dose all trace of intelligence disap- 
pears. When old Sly is stretched on the ground insensible from drink and snoring in 
the mud, he excites compassion and disgust : 

O monstrous beast ! liow like a swine he lies ! 
Grim death, how foul and loathsome is thine image." 

Charles Richet, in Revue des Deux Mondes. 

Drunkenness and Insanity. — " The connection between drunkenness and 
crime, and between drunkenness and poverty is close and unvarying in its effect upon 
society. The remarkable increase of insanity in recent years may in part be traced to 
the use of intoxicating beverages. It has been asserted that at least seven-tenths of 
all the crime and poverty and calamity to the people of the United States spring from 
the abuse of liquors." — Dr J. E, Reeves. 

35. The Impairment of the Will. — The direst result of the 
taking of alcohol is seen in the loss of self-control. " The worst 
estate of man is that wherein he loses the knowledge and 
government of hiniself." It is in the formation of the drinking 
habit that alcohol too often works the absolute ruin of its 
devotee, in both body and mind. It is apt to be a continuous 
habit, having for its sequel the dethronement of the will. It 
may be stated, as the rule, that after forty years of age, a man 
who has formed this habit is unequal by his own strength of 
will to abandon it. Many men of fine intellectual capacity and 
amiable qualities have become intemperate, and have so con- 
tinued, as long as their efforts to get free again have not been 
supplemented by outside and enforced restraint. It is for such 
as these that inebriate asylums have been built. Other hard 
drinkers drift into violence and crime, and finally find a curative 
restraint within prison walls. The benumbing effects of drink- 
ing habits upon the moral being of man is universally known. 
" All delicacy, courtesy and self-respect are gone ; the sense of 
justice and of right is faint or quite extinct ; there is no vice 
into which the victim of drunkenness does not easily slide, and 
no crime from which he can be expected to refrain. Between 
this condition and insanity there is but a single step," and death, 
in a worldly sense a deliverance, in spite of many an effort to 
rally, " terminates the miserable scene ; one by one lights have 



122 THE NERVOUS SYSTEM. 

been removed from the banquet of folly, and the last is now 
extinguished."'* 

36. An illustration of the disadvantage of drunkenness to the 
moral tone of a communit}' may be drawn from the results of 
the labors of Father Mathew, about forty years ago, as a tem- 
perance reformer. In the five years, 1838-1842, the consump- 
tion of whiskey in Ireland fell 50 per cent., the crimes of 
violence falling from 64,520 to 47,027, and executions from 59 
in the first year to 1 in the last year. 

Alcohol and Crime.— Thirty years of judicial experience have taught me that 
of the crimes which judges are called upon to try, and upon which sentences of the 
law are pronounced, more than eight-tenths of them involving any degree of violence 
in their character are directly traceable to the liquor shops. How often have I had 
young men look up at me when I asked them what they had to say why the sentence 
of the law should not be pronounced, declare, " I should never have done this crime if 
it were not for drink. Rum was my i-uin ; rum struck the blow and not my hand, that 
killed the man for whose death I am tried ; rum has caused me to beat my wife and 
injm-e my helpless child or to do the act which now confines me to a prison." — Judge 
KoaJi Davis. 

37. The Poisonous Effects of Alcohol. — Alcohol is, in 
the main, a narcotic poison in its efiects upon himian beings ; 
although the visible results vary immensely according to the 
quantity taken. If a sufiicient quantity is taken to cause any 
visible result, a condition, known as stimidation, is observed.! 



* Tlie Effects of mild Stimulation. — " Words of caution to young men con- 
cerning the iiijurious effects of tobacco, as well as indulgence in wine or the pleasures 
of the table, elicit, in ninety-nine out of one hundred cases, the reply, ' It does not 
hurt me.' Does not hurt you I Wait and see. In years to come, when you ought to 
l)e in your prime, you will be a poor, nervous, irritable, nerve-dried creature. Your 
liands will tremble, your head ^^^ll ache, your sleep be fitful and disturbed, your 
digestion impaired ; in short, the unnatural and transient pleasure at one end of your 
life will be more than counterlialanced by the discomfort and misery at the other. It 
is a truth of the greatest moment, which ought to be so impressed upon the mind as to 
l>e always rising up within it, that transgression's of the Iav:s of health, not punished at 
one end of life, are sure to be at the other." — -7. R. BlocJc on the Ten Laics of Health. 

t "Suppose, for instance, you measure your muscular strength with a 'health lift' 
or djTiamometer (by which muscular exertion can be accurately measured), and then 
take some of tlie drink, in the strength-inspiring power of which j'ou have most confi- 
dence, and when you are most exhilarated by it and feel as if you could shoulder a 
large fragment of Mount Oljnnpus "measure your sti-ength again. Tlie drink has fooled 
you, that is all. Yon felt that you were stronger than natural ; you find that the nar- 
cotic has Ijeen true to its pai-alyzing nature and that you are weaker. Tlien, after a 



THE NERVOUS SYSTEM. 123 

If an extremely large dose is taken, a state of stupor follows, 
and death lias been known to result in some cases. Between 
these two extremes there may be a variety of manifestations. 
As a stimulant, it appears to many to have a kindly action, to 
cause a glow and sense of warmth, to increase muscular activity, 
and to make the mind and organs of speech more nimble. 
Alcohol is not the only narcotic poison that exercises this influ- 
ence, which is not kindly, but is, in fact, the first indication of 
a paralysis of a portion of the nervous system."^ 

Most of the habitual takers of alcohol freely admit that they 
are injured by it in one way or another, and still they continue 
in their indulgence. In such cases, the mental balance is 
already lost : for a person to covet that which he knows to be 
hurtful to him, is manifestly not the sign of a sound mind. 

38. Tobacco and its Effects. — Tobacco, familiarly known as 
" the weed," is an annual plant said to be a native of America. 
It grows to the height of several feet, with leaves of a pale 
green color. These leaves, when dried, are made into cigars, 
chewing tobacco, and snuff, which are extensively used through- 
out the civilized world. 

39. Tobacco as a Poison. — Tobacco is a poison to the 

time, when the drug has spent itself and reaction (so called) comes on, and you feel 
weak and prostrated, measure your strength once more. Fooled again ; the stuff has 
fooled you twice. When you felt yourself strong you were weak, and now when you 
feel yourself weak you find yourself stronger- your natural strength is returning, and 
what you have called reaction is in reality recovery from the weakening effects of the 
narcotic." — Dr. A. F. Kinne. 

* " Here is a company of 'jolly good fellows ' all standing on their feet, their faces red 
and radiant, and all swinging their arms and talking at once. These men have been 
taking alcohol, and, surely, you will say, it has stimulated them. But if you will 
attend for a moment to wliat they are saying, you will see tliat there is no true brain- 
stimulation about it. We shall be reminded rather of what Addison says of the differ- 
ence between the mind of the wise man and that of the fool: " There are infinite, 
numberless extravagancies, and a succession of vanities which pass through both. The 
great difference is that the first knows how to pick and cull his thoughts for conversa- 
tion, by suppressing some and comnmnicating others ; whereas the other lets then\ all 
indifferently fly out in words? The case with these revelers is precisely this. The 
poison which they have taken has paralyzed their conservative faculties, and the talk- 
ing propensity is running on without anything to hold it in check and regulate it."— 
Dr. A. F. Kinnc. 



124 THE NERVOUS SYSTEM. 

young, and is far more hurtful to the adult than is generally 
supposed. It may be stated as a rule that there are few persons 
who use it habitually that do not suffer injury from it. The 
injury is mainly caused by what is known as " nicotine," one of 
the narcotic poisons, and particularly prominent in tobacco. 
Some of the effects of its limited use are nausea, vomiting, ver- 
tigo, and weakness; and its prolonged use, by those who are 
sensitive to it, often results in convulsions and other like sjTiip- 
toms, together with an irritability and weakened condition of 
the heart known to physicians as the " tobacco-heart." 

40. Effects on the Young. — Of the pernicious influence of 
the use of tobacco upon the young, the testimony of the Naval 
and Military Academies of the country is very decided. It has 
at times been allowed in both institutions, but at present it is 
forbidden, on the gTOund that its use is attended with serious 
damage to health. It is stated that its prohibition at the Naval 
Academy in 1881 was received with unanimous approval by 
the officers in charge and with " great joy by many of the 
cadets." Tremor of the muscles, caused by smoking, was very 
noticeable in the drawings that form so important a part of 
the cadets' work. A teacher of drawing, of fourteen years 
experience, has said that he can always tell from the character 
of the lines in the drawings whether or not the pupils used 
tobacco."^ Its avoidance has resulted in the reduced number of 
minor ailments that swelled the sick-list in years when its use 
was unrestricted. 

Athletes and other persons who engage in running matches 
and the like, are commonly not allowed to use either alcohol or 
tobacco while they are " in training "; their use interferes with 
the fullest development of muscular strength, 

* Prof. Mantegazza, of Florence, Italy, a distinguished sanitarian and physician, 
testifies that "Tobacco is never necessary; it is always hurtful to hoys and young 
men, to weak people and tliose disposed to consumption. * * * * All good citizens 
should try to put a stop to the general invasion of tobacco, which threatens to involve 
the whole of Europe in a dense cloud of smoke, which poisons even those who do not 
smoke." 



THE NERVOUS SYSTEM. 125 

41. Cigarette-Smoking. — This form of taking tobacco is 
injurious in two particulars that do not apply to the other 
forms. The smoker of cigarettes, either voluntarily or involun- 
tarily, takes into liis lungs a very large amount of smoke, and 
with it, that hurtful element, carbonic oxide. Again, there is 
an excessive amount of adulteration of the tobacco in cigarettes ; 
and one substance, opium, is largely so used and is extremely 
injurious. 

42. Snuff-Taking.— In addition to the hurtful effects of 
tobacco generally, snuff-taking is notoriously injurious to the 
senses of smell and taste, and to the voice. 

"The end of all science is to secure long life and good health to the individual and 
the race, and it ought to be a part of the rational creed of every good man and woman 
to abjure the use of tobacco and keep others from falling into the vice."— Dr. C. R. 
Drysdale. 

"Of tobacco, Franklin said that he could not think it had ever done much good in 
the world, since he never knew a person who used it habitually who would recommend 
another to do the same." 

" Tobacco is certainly not a food for man, nor has it much value as a medicine. The 
tobacco-worm is the only animal known to thrive upon it." — F. H. Hamilton. 

An illustration of the depressing influence of tobacco is given by Dr. Jacob Bigelow, 
who states that soldiers, when wishing to shirk duty and get on tlie sick-list, sometimes 
succeed in bringing on the symptoms of alarming illness by wearing a piece of tobacco 
under each arm-pit. Tlie skin absorbs sufficient of the poison to affect the general 
system to a marked degree. 

43. Narcotics. — The term narcotic is applied to different sub- 
stances derived chiefly from the vegetable kingdom, which 
have the wonderful property of quieting pain and causing 
sleep. Next in importance to alcohol — which belongs to the 
narcotics — are opium (and its preparations), chloral hydrate, 
hasheesh and cliloroform. 

44. Opium. — Opium is the thickened juice of the poppy- 
plant of India, and is commonly regarded as the most important 
of the narcotics. Its active principle is morpliine, which gives 
the soothing property to laudanum, paregoric, and Dover's 
powders. It is also used in nostrums to put infants to sleep : 
but unwisely used often brings on a sleep that knows no wak- 
ino-. 



126 THE NERVOUS SYSTEM. 

45. Effects of Opium. — Opium is particularly injurious 
to the young, even small doses sometimes producing alarming 
symptoms. Upon adults the external effects are not as notice- 
able as are those of alcohol, but the mind is more deeply stirred 
and the flow of ideas more copious. 

46. Danger from Opiates. — The use of opium for relieving 
pain has been known for hundreds of years. The enchanting 
sense of relief to suffering wrought by opiates leads to the mor- 
phine habit, commonly called opium-eating. It will be seen, 
therefore, why such great care is exercised by physicians in ad- 
ministering opiates, lest their patients afterward fall into the 
habit of taking them without medical advice. 

"The opium eater loses none of his moral sensibilities or aspirations ; he wishes and 
longs as earnestly as ever to realize what he believes possible and feels to be exacted 
by duty ; but his intellectual appi'ehensions of what is possible infinitely outruns its 
power not of execution only but even the power to attempt. He lies under the weight 
of incubus and nightmare ; he lies in sight of all that he would fain perform, just as a 
man forcibly confined to his bed by the mortal languor of a relaxing disease, who is 
compelled to witness injury and outrage offered to some object of his tenderest love ; 
he curses the spells which chain him down from motion ; he would lay down his life 
if he might but get up and walk ; but he is powerless as an infant and cannot even 
attempt to rise." — De Quincy's Confessions of mi O'pium Eater. 

47. Physiological Effects of Opium. — The frequent use of 
opium disturbs and weakens the stomach as well as the other 
digestive organs ; hence we invariably find the opium-eater to be 
a lean, yellow, sallow personage. His muscular and mental 
powers are impaired, and his will is terribly enfeebled. Tliis 
dreadful habit can be broken only with unspeakable suffering to 
its victim. 

48. Chloral Hydrate. — Chloral hydrate, commonly called 
chloral, is produced from alcohol, but its power as a sedative 
Avas not generally known until within the past twenty years. 
It also is a destroyer of appetite as well as of digestion, unless 
prescribed in proper doses, and the unfortunates once given 
over to it find themselves unable to sleep without its continued 
use. It should never be taken except under the direction of a 
physician. 



THE NERVOUS SYSTEM. 127 

49. Hasheesh. — Hasheesh, the juice of Indian hemp, is said 
to be used by millions of the inhabitants of Asia. It is not 
much known in the Avestern countries. In the East the excite- 
ment caused by its use takes the form of furious madness, lead- 
ing its victim to commit acts of violence and murder. Hence 
the term " hasheeshers " in our language has come to be synony- 
mous with assassins. 

"As everybody knows, the intoxication caused by alcoholic liquors, by hasheesh, 
by opium, after a first period of excitement, brings about a notable impairment of the 
will. The individual is more or less conscious of this : other persons see it more 
clearly. Soon— especially under the influence of alcohol— the weakening of the will 
becomes excessive. The extravagances, violences and crimes committed in this state 
are innumerable."— Dr. T. Ribot. 

50. Chlopofopm. — Chloroform, another product from alcohol, 
is used by inhalation when surgical operations are to be per- 
formed. As it is very powerful and subtle in its action, the 
imskilful use of it is dangerous in the extreme. The habit of 
taking chloroform by those who are great physical sufferers, or 
whose constitutions have been wrecked by the use of other nar- 
cotics, should be discouraged. It too often happens that the 
career of such is short, for the drug may easily be taken in 
excess and so cause death. 

51. Sleep Produced by Narcotics. — Opium and the opiates 
have the power of quieting the activity of the brain, and of 
compelling sleep. This may be a blessed action if skilfully 
applied by the physician, but not so applied it is the source of 
infinite peril. The sleep so caused differs from natural, restful 
slumber, especially in the fact that the after effects are commonly 
depressing and disturbing to the brain to the extent of being 
harder to bear than the wakefulness on account of which the 
drugs are taken. 

Yery young persons are especially subject to injury by sleep- 
producing medicines ; and many are the deaths that have been 
caused among infants by the giving of " soothing syrups," " cor- 
dials " and " anodynes " that are so freely made and sold for the 
purpose of compelling sleep. 



128 THE NERVOUS SYSTEM. 

52. Results of the Use of Narcotics.— The use of any of 

these narcotics, without proper medical advice, is their abuse. 
In this way they become powerful for harm. They are no 
longer remedies, but poisons. Self -prescribed, they have a thou- 
sand times been the instrument of unintentional suicide. 

The Narcotics and Digrestion.— Tlie habitual use of opium and other nar- 
cotic drugs is unfriendly to digestion, leading to nausea and a distaste for wholesome 
food. The vigor of the organs of digestion is impaired. 

Tlie disturbing eflfects of tobacco, in producing nausea and vomiting, is well known ; 
and is almost the invariable experience of all beginners in the use of that substance ; 
loss of appetite is a very frequent result of the habitual use of it. 



The Emotions Influence the Bodily Health.— " The exciting emotions 
which are pleasurable, such as joy and hope, are of a kind that seldom tend to a dan- 
gerous excess, and may be regarded as exercising generally an eminently healthful 
influence upon the body. Hilarity is a great refresher and strengthener of life. 
Laughter is a wholesome exercise, which, beginning at the lungs, diaphragm, and con- 
nected muscles, is continued to the whole body, ' shaking the sides,' and causing that 
jelly-like vibration of the frame of which we are so agreeably conscious when under 
its influence. The heart beats more briskly, but with a safe regularity of action, 
and sends the blood to the smallest and most distant vessel. The face glows -with 
warmth and color, the eye brightens, and the temperature of the whole body is mod- 
erately i-aised. With the universal pleasurable sensation there comes a disposition of 
every organ to healthy action. When hilarity and its ordinary expression of laughter 
become habitual, the insensible perspiration of the skin is increased, the breathing 
quickened, the lungs and chest expanded, the api)etite and digestion strengthened, 
and nutrition consequently increased. Tlie old proverb, ' Laugh and grow fat," states 
a scientific truth. The influence of laughter upon the body is recognized by Shakspere, 
in his description of the 'spare Cassius '— ' Seldom he smiles.' ' To be free-minded and 
cheerfully disposed at hours of meat, and sleep, and exercise, is one of the best precepts 
of long-lasting.' Such is the testimony of Lord Bacon to the favorable influence of the 
pleasurable emotions upon the body. Tlie depressing emotions, such as fear, anxiety, 
and grief, are always fatal to health, and frequent causes of death. There is an Eastern 
apologue which describes a stranger on the road meeting the Plague coming out of 
Bagdad. ' You have been committing great havoc there," said the traveler, pointing to 
the city. ' Not so great ! ' replied the Plague. ' I only killed one-third of those who 
died ; the other two thirds killed themselves with fright.' "—The Boole of nealth. 



NERVOUS SYSTEM. 129 

QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1. State fully Avhat is meant by the term vegetable function 106 

2. To what is man indebted for his position in the animal creation ? 106 

3. What can you state on the subject of special organs for separate functions ?. . . 107 

4. Describe, as fully as you can, the structure of the nervous system 107 

5. Describe the brain, its location, size, shape and structure 109 

6. Describe the brain proper, or cerebrum 109 

7. Describe the cerebellum, or little brain Ill 

8. Describe the spinal cord 112 

9. What are the spinal nerves, and how are they arranged ? 113 

10. Give and illustrate the function of nerve fibres 114 

11. Describe and illustrate the sympathetic system of nerves 114 

12. Explain Avhat is meant by the functions of the nerves, and give the illustration 115 

13. Wliat can you state of the rate of message-motion along a nerve ? 116 

14. "VNTiat are the functions of the spinal cord ? 116 

15. What experiments, with results, upon the spinal cord are noted ? 116 

16. Explain how injury of the cord may produce paralysis of motion in one leg, 

and at the same time a loss of sensation in the other 116 

17. Explain how, if the right hand be hurt, the left side of the brain is made to 

feel the pain 117 

IS. Now, explain as fully as you can the direction of the fibres of the cord 117 

19. What is the reflex action of the cord, and its use ?. 117 

20. What is the medulla oblongata ? 118 

21. What are the functions of the medulla oblongata ? 118 

22. What are the functions of the cerebellum ? 119 

23. What is the function of the cerebrum ? 119 

24. In what way does the size of the brain generally indicate the character of the 

man? 119 

25. What facts show that the gray substance of the brain is insensitive ? 119 

26. Upon what does the faculty of language seem to depend ? 119 

27. Of what importance is the reflex action of the brain ? 119 

28. What changes are produced in the brain by the use of alcohol ? 120 

29. What are the effects upon the mind ? 120 

30. How does the will suffer by alcohol ? 121 

31. What were the results of Father Matthew's labors in behalf of temiierance ?. . . 122 

32. What is said of the poisonous effects of alcohol upon man ? 122 

33. What are the uses of tobacco ? 123 

34. What is the most prominent element in tobacco and what can you say of it ?. . 124 

35. What has observation shown to be the effects of tobacco upon the youth ? 124 

36. What can you say of cigarette-smoking ? 125 

37. What is said of snuff"-taking ? 125 

38. What do you understand by the general term " Narcotic ? " Name some of 

its forms 125 

39. What is opium and in what medicines is it found ?. 125 

40. Give the first effects of opium 126 

41. What is the danger to be feared by its use ? 126 

42. What results from continued use of opium ? 126 

43. What can you say of chloral-hydrate ? 126 

44. Say Avhat you can of hasheesh 127 

45. How is chloroform produced and how is it sometimes used ? 127 

46. What conclusions do you draw as to the use of narcotics ? 128 



CHAPTER IX. 

The Special Senses. 

The Production of Sensations — Variety of Sensations — Gen- 
eral Sensibility— Pain and Its Function — Special Sensa- 
tion, Touch, Taste, Smell, Sight, and Hearing — The 
Hand, the Organ of Touch — The Sense of Touch — 
Delicacy of Touch — Sensation of Temperature and 
Weight — The Tongue the Organ of Taste — The Nerves 
of Taste — The Sense of Taste and its Relations with 
the other Senses — The Influence of Education on the 
Taste — The Nasal Cavities, or the Organs of Smell — 
The Olfactory Nerve — The Uses of the Sense of Smell 
— ^The Sense of Sight — Light — The Optic Nerve — The 
Eyeball and Its Coverings — The Function of the Iris — 
The Sclerotic, Choroid, and Retina — The Tears and 
their Function — The Movements of the Eyeball — The 
Function of Accommodation — The Sense of Hearing 
and Sound — The Ear, or the Organ of Hearing— The 
External, Middle, and Internal Ear. 

I. Production of Sensations. — We have already seen that 
the true centre of sensation is some organ within the sknll, 
probably among the gray masses at the base of the brain ; but 
the mind never perceives impressions at that point, but, on the 
contrary, always refers them to the external organs of sensation. 
Hence it is convenient to say, that those outer parts possess the 
property of sensibility. For instance, we say that we hear with 
the ear, taste with the tongue, and feel with the fingers. That 



THE SPECIAL SENSES. 131 

this is not the exact truth is proven by the fact, that whenever 
the nerve connecting one of these organs with the brain is 
severed, it at once loses its capacity for sensation. 

2. Consciousness, another faculty of the brain, is necessary 
to complete a sensation. During sleep, and in other uncon- 
scious states, the usual impressions are presented to the ear, the 
nose, and the skin, but they fail to excite sensations, because 
the nerve-centres are inactive. In profound insensibility, from 
chloroform or ether, a limb may be removed without occasioning 
the least feeling. 

3. Variety of Sensations. — All animals have some degree 
of sensibility. It is of course feeble and indistinct in the lower 
forms of Ufe, but increases in "power and variety as we ascend 
the scale. In the earth-worm, the nervous system is very 
simple, the sensibility being moderate and alike in all parts : 
hence, if its body be cut into two pieces, each piece will have 
the same degree of feeling as before. As we approach man, 
however, the sensations multiply and become more acute ; the 
organs are more complex, and special parts are endowed with 
special gifts. These special organs cannot be separated from 
the rest of the body without the loss of the functions they are 
designed to exercise. 

4. The lowest form of sensation, that of simple contact, is 
possessed by the lowest of the animal creation. The highest 
forms are those by which we are enabled to know the properties 
of external objects, such as shape, size, sound and color. Sen- 
sations are modified by use. They become more acute and 
powerful by moderate exercise ; or, they are dulled by undue 
excitement. The former is shown by the acute hearing of the 
Indian, by the sharp sight of the sailor, and by the delicate 
touch of the blind. The latter is exemplified by the impaired 
hearing of the boiler-maker, and the depraved taste of hini who 
uses pungent condiments with his food. Again, impressions 
habitually presented may not be consciously felt ; as is the case 
with the rumbling of carriages in a neighboring street, or the 



132 THE SPECIAL SENSES. 

regular ticking of a clock. All sensations become less acute 
with the advance of age, especially hearing and vision. 

5. General Sensibility. — There is a property possessed by 
nearly all parts of the human body which we call general sensi- 
bility. The brain is wholly insensitive, and may be cut or 
pinched without pain. The same is true of the nails, hair, the 
scarf-skin or external covering of the body, and a few other 
structures. In these parts no nerves are found. On the other 
hand, the sensibility of the true skin, and of mucous membranes, 
as of the eye and nose, is exquisite, these organs having a large 
supply of sensory nerve-fibres. The bones and tendons have 
less of these fibres, and are only moderately sensitive. 

6. The sensibility of any part of the body, then, depends 
upon the number of nerves present ; and, as a rule, the nervous 
supply is proportional to the importance of the part, and to its 
liability to injury. ^Vlien, therefore, a surgical operation is 
performed, the most painful part of it is the incision through 
the skin ; the muscles, cartilage, and bone being comparatively 
mthout sensation. Hence, if we could benumb the surface, 
certain of the lesser operations might be undergone without 
great inconvenience. This is, in fact, very successfully accom- 
plished by means of the cold produced by throwing a spray of 
ether, or of some other rapidly evaporating liquid, upon the part 
to be cut. 

7. Tickling is a modification of general sensibility. At first, 
it excites a pleasurable sensation, but this soon passes into pain. 
It is only present in those parts where the sense of touch is 
feeble. But all impressions are not received from without : 
there are, also, certain internal sensations, as they are called, 
which depend upon the condition of the internal organs, such 
as appetite, hunger, thirst, dizziness when looking down from 
some lofty position, drowsiness, fatigue, and other feelings of 
comfort or discomfort. General sensibility, whether of the 
internal or external organs of the body, chiefly depends upon 
the sensory fibres of the spinal aerve. The fa.ce, however, is. 



THE SPECIAL SENSES. 133 

supplied by the sensory cranial nerves. The sympathetic sys- 
tem has a low grade of feeling in health ; but disease in the 
parts served by it arouses an intense degree of pain. 

8. The Sensation of Pain. — \VTiat then is ijcdn? Is it 
identical with ordinary sensibility 1 There seems to be some 
necessary connection between the two feelings, for they take 
place through the same channels, and they are alike intense in 
the same situations. But sensibility habitually contributes to 
our sources of pleasure, the very opposite of pain ; hence, these 
feelings cannot be identical. 

9. Pain must, therefore, be a modification of the general 
sensibility which follows an excessive degree of excitement of 
the nerves ; there being a natural limit to the amount of stimu- 
lation which they will sustain. So long as this limit is 
observed, the part excited may be said to be simply sensitive ; 
but when it is exceeded, the impression becomes painful. This 
difference between sensibility and pain is well shown by the 
effects of sunlight upon the eye. The indirect illumination of 
the sun arouses only the former feeling, and is indispensable to 
our comfort and existence ; while the direct ray received into 
the eye occasions great pain. 

10. The Uses of Pain. — The dread of pain is a valuable 
monitor to the body. It puts us on our guard in the presence 
of danger ; teaches moderation in the use of our powers ; indi- 
cates the approach of disease ; and calls attention to it when 
present. The word disease, in fact, according to its original 
use, had reference simply to the pain, or want of ease, which 
commonly attends disordered health. A^Hien we observe the 
serious mishaps which occur when sensibility and pain are 
absent, we cannot fail to appreciate its value. For example, a 
paralytic in taking a foot-bath, forgets to test its temperature, 
and putting his limbs into water while it is too hot, is severely 
scalded without knowing it. 

11. Pain is, indeed, a present evil, but its relations with the 
future prove its mission merciful. Considered in the light of 



134 THE SPECIAL SENSES. 

results, pain has a use above that of pleasure ; for while the 
immoderate pursuit of the latter leads to harm, the tendency of 
pain is to restrict the hurtful courses of life, and in this man- 
ner to protect the body. 

12. As to painful sensation among the inferior animals, the 
plan of IS^ature seems to be, that the higher the intelligence of 
the creature, and the more complete its power of defence, the 
more acute is its sensibility. We infer, therefore, that animals 
low in the scale of existence, and helpless, are not very liable to 
suffer pain. 

13. Special Sensation. — The sensations of simple contact 
and pain are felt by nearly all parts of the system, whether ex- 
ternal or internal, and are the necessary consequence of the 
general sensibility. Besides these feelings, man is endowed 
with certain special sensations, which are positive and distinct 
in character, and which he can call into exercise at will, and 
employ in the pursuit of knowledge. 

14. These distinct and active faculties are termed the special 
senses, and are five in number, viz.. Touch, Taste, Smell, Sight, 
and Hearing. For the exercise of these senses, special organs 
are furnished, such as the hand, the tongue, the nose, the eye, 
and the ear. The manner in which the nerves of special sense 
terminate varies in the case of each organ, so that each is 
adapted to one set of sensations alone, and is incapable of per- 
ceiving any other. Thus the nerve of hearing is excited by the 
waves of sound, and not by those of light, while the reverse is 
true of the nerve of sight. 

15. By some writers six senses are accorded to man; the 
additional one being either the sense of temperature, for as we 
shall presently see this is not the same as touch ; or, according 
to others, the muscular sense by which we are enabled to esti- 
mate the weights of bodies. The latter also differs in some 
respects from the sense of touch. 

16. Organs of Touch. — The sense of touch is possessed by 
nearly all portions of the general surface of the body, but it 



THE SPECIAL SENSES. 135 

finds its liighest development in the hands. The human hand 
is properly regarded as the model organ of touch. The minute 
structure of the skin fits it admirably for this form of sensation : 
the cuticle, or scarf-skin, is fine and flexible, while the cutis, or 
true skin, contains multitudes of nerve-filaments, arranged in 
rows of ixipillce, or cone-like projections, about one-hundredth 
of an inch in length. It is estimated that there are 20,000 of 
these papillse in a square incli of the palmar surface of the hand. 
Kow, although the nerves of the cutis are the instruments by 
which impressions are received and transmitted to the brain, yet 
the cuticle is essential to the sensation of touch. This is shown 
by the fact that whenever the true skin is laid bare, as by a 
burn or blister, the only feeling it experiences from contact is 
one of pain, not that of touch. 

17. The office of the cuticle is thus made evident : it is to 
shield the nerve filaments from direct contact with external 
objects. At the tips of the fingers, where touch is most delicate, 
the skin rests upon a cushion of elastic material, and receives 
firmness and permanence of shape by means of the nail placed 
upon the less sensitive side. Besides these favorable conditions, 
the form of the arm is such, and its motions are so easy and 
varied, that we are able to apply the test of touch in a great 
number of directions. The slender, tapering fingers, with 
their pliant joints, together with the thumb, enable the hand 
to grasp a great variety of objects; so that great as are the 
delicacy and grace of the hand, it is not wanting in the 
elements of power. 

18. The Sense of Touch. — Touch is the simplest of the 
senses. It is that which the child first calls into exercise, and 
it is that which is in the most constant use throughout life. 
We are brought by the touch into the most intimate relations 
with external objects, and by it we learn the greater number, if 
not the most important, of the properties of these objects ; such 
as size, figure, solidity, motion, and smoothness or rouglmess of 
surface. 



136 THE SPECIAL SENSES. 

19. The sense of touch assists the other senses, especially that 
of sight, giving foundation and reality to their perceptions. 
Without it, the impressions received by the eye would be as 
vague and unreal as -the figures that float through our dreams. 
A boy who had been blind from birth, at the age of twelve 
years received sight by a means of a surgical operation : at first, 
he was unable to distinguish between a globe and a circular 
card, of the same color, before he had touched them. After 
that, he at once recognized the difi'erence in their form. He 
knew the peculiarities of a dog and a cat by feeling, but not 
by sight, until one day, happening to take up the cat, he recog- 
nized the connection of the two sorts of impressions, those of 
touch and sight ; and then, putting the cat down, he said : "So 
puss, I shall know you next time." 

20. Of all the senses, touch is considered the least liable to 
error ; yet, if that part of the skin by which the sense is exer- 
cised is removed from its customary position, a false impression 

►may be created in the mind. This is well illustrated by an ex- 
periment, which dates from the time of Aristotle. If we cross 




Fig. 34 



the middle finger behind the fore-finger, and then roll a marble, 
or some small object, upon the tips of the fingers (see Fig. 34), 
the impression will be that two marbles are felt. If the fingers, 
thus transposed, be applied to the end of the tongue, two 
tongues will be felt, 

21. The Delicacy of Touch. — Although the hand is the 



THE SPECIAL SENSES. 137 

proper organ of this sense, yet it is exercised by various 
parts of the body, their degree of sensibility being proportional 
to the number of papillae they contain. The varying degrees of 
tactile delicacy of the different parts of the surface have been 
measured, in an ingenious manner, by means of a pair of com- 
passes, tipped with small pieces of cork. The two points of 
the compasses are touched at the same moment to the skin, the 
eyes being closed, and it is found that, in sensitive parts, the 
distance between the points may be quite slight, and yet each 
be plainly felt ; while, in less sensitive parts, the points of the 
compasses are felt as a single point, although they are separated 
one or two inches. 

22. At the tips of the fingers, the distance between the points 
being one-twentieth of an inch, a double impression is felt. 
The distance must be twice as great, for the palm ; four times 
as great, for the lips ; and, on the forehead, it must be twenty 
times greater. At the middle of the back, where the touch is 
least acute, the points must be separated more than two inches 
before they can be separately felt. Therefore, the sense of 
touch in the fingers is said to be fifty times more delicate than 
upon the posterior surface of the body. 

23. Exquisite delicacy of touch is attained by practice. 
This is shown in many of the lighter and more graceful em- 
ployments of daily life. Without it, the skill of the painter, 
sculptor, and musician would be rude indeed. By training, 
also, the physician acquires the tadus erudifus, or discriminating 
touch : but among the blind, delicacy of touch is most remark- 
able, and it here finds its highest value ; for its possession, in 
a measure, compensates the loss of sight by enabling them 
to read, by means of raised letters, to work with certain tools, 
and even to play upon musical instruments. A person born 
without sight, and without hearing or voice, may, by the educa- 
tion of the touch, be rescued from apparent imbecility, and be 
taught not only to read and write, but even to perform house- 
hold and other useful labors. 



138 THE SPECIAL SENSES. 

24. Sensations of Tempepatupe and Weight. — Each of 
these sensations has been described by the physiologists as a 
special sense, and they are rival candidates, so to speak, for the 
position and title of the sixth sense. In the sensation of tem- 
perature, or the thermal sense, touch bears a part, but the two 
feelings appear to be distinct. In proof of this, we observe, 
firstly, that they are not alike intense in the same situations ; 
as, for example, the skin of the face and elbow, where the 
sense of touch is feeble, is very sensitive to impressions of heat 
and cold. Secondly, the ability to recognize temperature may 
be lost by paralysis, while the sensibility of touch remains 
unaffected. AAHien the skin comes in contact with a very hot 
substance, the sensation felt is that of pain, not of touch. In 
like manner, a very cold substance causes pain, not the feeling 
of cold. So that a red-hot iron, and solid carbonic acid (the 
temperature of which is 108° below zero), feel alike; and each, 
if pressed slightly, will produce a blister. 

25. The muscular sense, by some considered distinct from 
touch, gives rise to the sensations of weight, and other forms of 
external resistance. That this feeling exists, is shown by the 
following simple experiment. If the hand be placed flat upon 
a table, and a somewhat heavy weight be put into it, touch 
alone is exercised and a feeling of pressure results ; but if the 
hand be raised, a certain amount of muscular effort must be put 
forth, and thus the sensation of weight is recognized. Through 
the muscular sense, precision of effort is rendered possible ; for 
by it we learn to adjust the force exerted to the weight of the 
object to be lifted, moved, or carried. Without it, all our 
movements would necessarily become ill-regulated and spas- 
modic. 

26. The Opgan of Taste. — The tongue is the special 
organ of the sense of taste ; but the back part of the mouth 
also possesses this faculty. The tongue is a muscular organ, 
the muscles composing it being so numerous and interwoven as 
to give it the freedom and variety of motion which it possesses. 



THE SPECIAL SENSES. 139 

It can curve itself upward or downward ; it can extend or con- 
tract itself ; and, with its point, can sweep the cavity of the 
mouth, in all directions, in the search for scattered particles of 
food. 

27. The upper surface of the tongue is peculiar, being marked 
by the presence of innumerable jpapillce^ some of which are of 
microscopic size, resembling those that abound in the fingers, 
and in other parts of the body that have the sense of touch. 
Others are much larger, and give to the tongue its roughness of 
feeling and appearance. Through the medium of these papillae, 
the tongue receives impressions of touch and temperature, as 
well as taste ; indeed, its extremity is fully as delicate, in re- 
spect to tactile sensations, as the tips of the fingers themselves. 
It can recognize the two points of the compasses when sepa- 
rated not more than one-twenty-fourth of an inch; the back of 
it is much less sensitive to touch, while at the same time it is 
more highly sensitive to impressions of taste. 

28. Each lateral half of the tongue resembles the other in 
structure, and each receives the same number of nerves — three. 
One of these regulates motion, the other two are nerves of 
special sense. One of the latter supplies the front half of the 
tongue, and is called the gustatory nerve. This is a branch of 
the great cranial nerve, called the " fifth pair," which ramifies 
in all parts of the face. "The back of the tongue is endowed 
with the power of taste through a nerve known as the glosso- 
pliaryngealj because it is distributed both to the tongue and 
throat. This difference in the nervous supply of the tongue 
becomes significant, when we learn, as we shall presently, that 
each part of it perceives a different class of flavors. 

29. The Sense of Taste. — Taste is the special sense by 
means of which we discover the savors, or flavoring properties 
of the substances, Avhich come in contact with the tongue. 
Mere contact with the surface of the tongue, however, is not 
sufficient, but contact with the extremities of the nerves of 
taste within the papillae is required. In order that the sub- 



140 THE SPECIAL SENSES. 

stance to be tasted may penetrate the cells covering the nerves, 
it must either be liquid in form, or readily soluble in the watery 
secretion of the mouth, the saliva. The tongue must be moist 
also. If the substance be insoluble, as glass or sand, or the 
tongue dry, the sense of taste is not awakened. In sickness, 
when the tongue is heavily coated, the taste is very defective, 
or, as is frequently expressed, " nothing tastes aright." 

30. All portions of the tongue are not alike endowed with 
the sense of taste, that function being limited to the posterior 
third, and to the margin and tip of this organ. The soft palate, 
also, possesses the sense o"f taste ; hence, an article that has an 
agreeable flavor may very properly be spoken of as palatable, as 
is often done. All parts of the tongue do not perceive equally 
well the same flavors. Thus, the front extremity and margin, 
which is the portion supplied by the " fifth pair " of nerves, 
perceives more acutely sweet and sour tastes ; but the base of 
the tongue, supplied by the glosso-pliaryngeal nerve, is espe- 
cially sensitive to salt and bitter substances. The nerve of 
the front part of the tongue, as before stated, is in active 
sympathy with those of the face, wliile the relations of the 
other nerve are chiefly with the throat and stomach ; so that 
when an intensely sour taste is perceived, the countenance is 
involuntarily distorted, and is said to wear an acid expression. 
On the other hand, a very bitter taste affects certain internal 
organs, and occasions a sensation of nausea, or sickness of the 
stomach. 

31. Relations of Taste with other Senses. — Taste is not 
a simple sense. Certain other sensations, as those of touch, 
temperature, smell, and pain, are blended and confused with it : 
and certain so-called tastes are really sensations of another kind. 
Thus an astringent taste, like that of alum, is more properly an 
astringent feeling, and results from an impression made upon 
the nerves of touch, that ramify in the tongue. 

32. Taste is largely dependent upon the sense of smell. A 
considemble number of substances, like vanilla, coffee, and gar- 



THE SPECIAL SENSES. 141 

lie, which appear to possess a strong and distinct flavor, have in 
reahty a powerful odor, but only a feeble taste. When the 
sense of smell is interfered with by holding the nose, it becomes 
difficult to distinguish between substances of this class. The 
same effect is frequently observed when smell is blunted during 
an ordinary cold in the head. Sight, also, contributes to taste. 
With the eyes closed, food appears comparatively insipid ; and 
a person smoking tobacco in the dark is unable to determine by 
the taste whether his cigar is lighted or not. Accordingly, it is 
not a bad plan to close the nose and shut the eyes when about 
to swallow some disagreeable medicine. 

33. Influence of Education on the Taste. — The chief use 
of the sense of taste appears to be to act as a guide in the selec- 
tion of proper food. Hence its organs are properly placed at 
the entrance of the digestive canal. As a general rule, those 
articles which gratify the taste are wholesome ; while the oppo- 
site is true of those which impress it disagreeably. This state- 
ment is more exact in reference to the early years of life than 
to later years, when, by reason of mischievous habits, the sense 
of taste has become dulled or perverted. The desires of a child 
are simple; he is fully satisfied with plain and wholesome 
articles of diet, and must usually " learn to like " those which 
have a strongly marked flavor. Accordingly, it is far easier at 
this age to encourage the preference for plain food, and thus 
establish healthful habits, than later in life to uproot habits of 
indulgence in stimulating substances, after their ill effects begin 
to manifest themselves. 

34. The tastes of men present the most singular diversities, 
partly the result of necessity and partly of habit or education. 
The Esquimaux like the rank smell of whale oil, which is a 
kind of food admirably suited to the requirements of their icy 
climate ; and travelers who go from our climate to theirs are 
not slow to develop a liking for the same articles that the 
natives themselves enjoy. The sense of taste is rendered very 



142 THE SPECIAL SENSES. 

acute by education, as is shown in an especial manner by those 
who become professional " tasters " of tea and wine. 

35. The Sense of Smell— the Nasal Cavities. — The sense 
of smell is located in the delicate mucous membrane which lines 
the interior of the nose. That prominent feature of the face, 
the nose, which is merely the front boundary of the true nasal 
organ, is composed partly of bone and partly of cartilage. The 
upper part of it is united wdth the skull by means of a few 
small bones ; to which circumstance is due its permanence of 
shape. The lower portion, or tip of the nose, contains several 
thin pieces of cartilage, which render it flexible and better able 
to resist the effects of blows and pressure. Behind the nose we 
find quite a spacious chamber, separated from the mouth by the 
hard palate, forming the " roof of the mouth," and also by the soft 
palate (see Fig. 35) ; and divided into two cavities by a central 
partition running from before backward. 

36. These nasal cavities, constituting the true beginning of 
the air-passages, extend from the nose backward to the upper 
opening of the throat, and rise as high as the junction of the 
nose with the forehead. The inner wall of each cavity is 
straight and smooth ; but from the outer wall there jut into 
each cavity three small scroll-like bones. The structure of these 
bones is very light, and hence they have been called the 
"spongy" bones of the nose. In this manner, while the extent 
of surface is greatly increased by the formation of these winding 
passages, the cavities are rendered extremely narrow ; so much 
so, in fact, that a moderate swelling of the mucous membrane 
which lines them, as from a cold, is sufficient to obstruct the 
passage of air through them. 

37. The Nepve of Smell. — The internal surface of the nasal 
passages is covered by a delicate and sensitive mucous membrane. 
Its surface is quite extensive, following, as it does, all the 
inequalities produced by the curved spongy bones of the nose. 
The upper portion of it alone is the seat of smell, since that 
part alone receives branches from the " first pair " of cranial 



THE SPECIAL SENSES. 



143 



nerves, or the olfactory nerve, which is the special nerve of 
smell (see Fig. 32). In Fig. 35 is shown the distribution of 

this nerve, in the form 
of an intricate network 
upon the two upper 
spongy bones. The 
nerve itself (1) does 
not issue from the 
skull, but rests upon a 
thin bone which sepa- 
rates it from the cavity 
of the nose ; and the 
branches which proceed 
from it pass through 
openings. The engrav- 
right nasal cavity-; the 




Section of the Eight Nasal Cavity. 



this bone by means of numerous small 

ing represents the outer surface of the 

three wave-like inequalities, upon which the nervous network is 

spread out, are due to the spongy bones. The left cavity is 

supplied in the same manner. 

38. The nerves which ramify over the lower part of the 
membrane, and which endow it with sensibility to touch and 
pain, are branches of the " fifth pair " of nerves. An irritation 
applied to the parts where this nerve is distributed occasions 
sneezing, that is, a spasmodic contraction of the diaphragm ; the 
object of which is the expulsion of the irritating cause. The 
manner in which the olfactory nerve-fibres terminate is peculiar. 
Unlike the extremities of other nerves, which are covered in by 
a greater or less tliickness of tissue, these come directly to the 
surface of the mucous membrane, and thus come into very close 
contact with the odorous particles that are carried along by 
the respired air. 

39. The Uses of the Sense of Smell. — Smell is the special 
sense which enables us to appreciate odors. Touch, as we have 
seen, is largely concerned with solid bodies ; and taste, with 
fluids, or with solids in solution. Smell, on the other hand, is 



144 THE SPECIAL SENSES. 

designed to afford us information in reference to substances in a 
volatile or gaseous form. Invisible particles come from odorous 
bodies, and are brought by the respired air in contact with the 
terminal filaments of the olfactory nerve, upon which an agree- 
able or disagreeable impression is produced. The fineness of 
the particles that constitute odors is often so extreme, that they 
elude all attempts to measure or weigh them. A piece of musk, 
for instance, may be kept for several years, constantly emitting 
perfume, without any appreciable loss of weight. In other 
cases, a loss of substance is perceptible, such as the essential 
oils, which enter into the composition of the ordinary perfumes. 
40. Smell, like taste, aids us in the choice of proper food, 
leading us to reject such articles as have a rank or putrid odor, 
and which are, as a rule, unfit to be eaten. The highest useful- 
ness of this sense, however, consists in the protection it affords 
to the organs of respiration. Stationed at the gateways of the 
air-passages, it examines the current of air as it enters, and 
warns us of the presence of noxious gases, and of other and 
generally invisible enemies to health. Not all dangerous vapors 
are offensive, but almost all offensive vapors are unfit to be 
breathed. A number of small stiff hairs grow from the margin 
of the nostrils to prevent the entrance of dust and other atmos- 
pheric impurities, which would be alike injurious to the olfactory 
mucous membrane and to the lungs. The benevolent design of 
the Maker of our bodies may be observed in all parts of their 
mechanism ; but, probably, in none is it more clearly displayed 
than in connection with the sense of smell. 
► 41. The Sense of Sight. — Sight, or Vision, is the special 
sense by means of which we appreciate the color, form, size, 
distance, and other physical properties of the objects of external 
nature. Primarily, this sense furnishes us with information 
concerning the different shades of color and the different de- 
grees of brightness : these are the simple sensations of sight, 
such as the yellowness and glitter of a gold coin. In addition 
to these, there are composite visual sensations, produced by the 



THE SPECIAL SENSES. 145 

joint action of the other senses and by the use of the memory 
and judgment ; such as, in the case of the coin, its roundness, 
soUdity, size, its distance and direction from us. So that many 
of our sensations, commonly considered as due to sight, are in 
reahty the results of intellectual processes which take place 
instantaneously and unconsciously. 

42. Light. — The Optic Nerve. — Unlike the senses previ- 
ously considered — touch, taste, and smell — sight does not bring 
us into immediate contact with the bodies that are examined ; 
but, by it, we perceive the existence and qualities of objects 
that are at a greater or less distance from us. In the case of 
the stars, the distance is incalculable, while the book we read is 
removed but a few inches. Light is the agent which gives to 
this sense its wide range. The nature of this mysterious force 
is not kno^vn, and it is not here to be discussed ; since its study 
belongs more properly to the province of natural philosophy. 

43. It is sufficient, in this connection, to state that the 
theory of light now generally accepted, and which best explains 
the facts of optics, is that known as the undulatory theory. 
This theory supposes that there exists an intangible, elastic 
medium, which fills all space, and penetrates all transparent 
substances, and which is thrown into exceedingly rapid undula- 
tions or waves, by the sun and every other luminous body, the 
undulations moving not less than 186,000 miles in a second. 

44. These waves are thought to produce in the eye the sen- 
sation of light, in the same manner as the sonorous vibrations of 
the air produce in the ear the sensation of sound. That part of 
the eye which is sensitive to these waves is the expansion of 
the optic nerve. It is sensitive to no other impression than that 
of light, and it is the only nerve which is acted upon by this 
agent. The optic nerve, also called the " second pair " of cranial 
nerves, is the means of communication between the eye and the 
brain. 

45. The Organ of Sight. — The Eye. — The proximity of 
the eye to the brain, and the important part it performs in 



146 • THE SPECIAL SENSES. 

giving expression to the emotions, have given it the name of 
"the window of the soul." The exceeding beauty of its exter- 
nal parts, and the high value of its function, have long made 
this organ the subject of enthusiastic study. It is chiefly within 
the last twenty years, however, that this study has been success- 
ful and fruitful of practical results. Several ingenious instru- 
ments have been invented for the examination of the eye in 
health and disease, and new operations have been devised for 
the relief of blindness and of impaired vision. As a result, it is 
noAv a well-marked fact that, in civilized lands, the number of 
those who suffer from loss of sight is proportionally much less 
than in countries where science is less known and cultivated. 

46. The most obvious fact in respect to the apparatus of 
sight is that there are two eyes, which may either act together 
as one, and be fixed upon one object, or one eye may be used 
independently of the other. In consequence of this arrange- 
ment the loss of one eye does not necessitate blindness, and, in 
fact, it not infrequently happens that the sight of one eye may 
be long impaired or lost before the fact is discovered. We next 
notice that it is placed at the most elevated part of the body, in 
front, and near the brain. It also commands a wide range of 
view, being itself moved with great rapidity, and being further 
aided by the free motion of the head and neck. The organ of 
vision consists essentially of two parts : the optical instrument 
itself — the eyeball — and its enveloping parts, or the case in 
which the instrument is kept free from harm. The latter, 
which are external, and which we shall first consider, are chiefly 
the Orbits, the Eyelids, and the apparatus for the Tears. 

47. The Orbits. — The eyeball, which is a delicate organ, is 
well defended against external injury within the orbits or bony 
sockets of the head. These are deep conical hollows, bounded 
in part by the bones of the skull, and in part by those of the 
nose and cheek. The orbit juts out beyond the most exposed 
portion of the eyeball, as may be seen by laying a book over 
the eye, when it will be found that no part of the eyeball, un- 



THE SPECIAL SENSES. 



147 



less it be very prominent, will be touched by the book ; so that 
the only direction in which an injury is liable to be received is 
immediately in front of the eye. The overhanging brow is itself 
covered by a layer of thick skin, studded with short, stout hairs, 
which are so bent as to prevent the perspiration from running 
into the eye and obscuring vision. Through a hole in the bot- 
tom of the orbit, the nerve of sight passes outward from the 
brain. The orbit also contains a considerable amount of a fatty 
tissue, upon which, as upon an elastic cushion, the eye rests. 

48. The Eyelids. — The eyelids are two movable curtains, 

or folds, which, when shut, 
cover the front part of the 
orbit, and hide the eye from 
view. The upper lid is the 
larger, has a curved margin, 
and moves freely, while the 
lower lid is comparatively 
short and straight, and has 
but a slight degree of mo- 
tion (Fig. 36). Skin covers 
the exterior of the lids, 
while a fine mucous mem- 
brane lines their inner sur- 
face, and is likewise spread 
out over the entire front of 

the eyeball. This membrane, which is called the Conjunctiva, 
is highly sensitive, and thus plays an important part in protect- 
ing the 6ye against the lodgment of sand, ashes, chaff, and other 
foreign particles that are blown about in the air. This sensitive 
membrane will not endure the presence of these particles. If 
any find access, it causes a constant winking, a flow of tears, 
and other signs of irritation, until it is removed. 

49. The long, silky eyelashes, which garnish the edges of the 
lids, act like a sieve to prevent the entry of dust and the like ; 
and together with the lids, they regulate the amount of light 




Fig. 36.— Front View of the Right Eye. 
(Natural Size.) 

1. The Lachrymal, or tear gland, lying be- 
neath the upper eyelid. 

2. The Nasal Duct is shown by the dotted 
line. The * marks the orifice in the lower lid. 

The central black spot is the pupil ; surround- 
ing it is the iris; and the triangular white 
spaces are the visible portion of the sclerotic. 



148 



THE SPECIAL SENSES. 



wMch is permitted to enter the eye, so that it is shielded from 
a sudden flood or glare of light. The little points seen in 
the figure just within the line of the lashes, especially on the 
lower lid, represent the mouths of numerous little sebaceous 
glands (Fig. 37, D, D), such as are always found in the neigh- 




FiG. 37.— Vertical Section of the Eye. (Enlarged.) 



C, The Cornea. 

A, The Aqueous Humor. 
I, The Iris. 

P, The Pupil. 

L, The Crystalline Lens. 

H, The Ligament of the Lens. 

B, The Ciliary Process. 

V, The Cavity containing the Vitreous 
Humor. 



S, The Sclerotic 

Ch, The Choroid. 

R, The Retina. 

N, The Optic Nerve. 

DD, The Eyelids. 

X, The Levator Muscle of the Upper Lid. 

Y, The Upper Straight Muscle of the 

Eye. 
Z, The Lower Straight Muscle. 



borhood of hairs. These glands supply a thick, oily material 
which greases the edges of the lids and prevents their adhering 
together, and likewise prevents the overflow of the tears upon 
the cheek. 

50. The Lachrymal Fluid, op the Tears. — Just within the 
outer part of the bony arch of the brow, where the bone may be 
felt to be sharper than in other positions, is lodged a little organ 
called the lachrymal gland, the situation of which is indicated in 



THE SPECIAL SENSES. 149 

Fig. 36, 1. This is the gland whence flows the watery secre- 
tion, commonly called the tears, which is designed to perform 
an exceedingly important duty in lubricating the lids, and in 
keeping the exposed surface of the eyeball moist and transparent. 
For, without this or some similar liquid, the front of the eye 
would speedily become dry and lustreless, like that of a fish 
which has been removed from the water : the simple exposure 
of the eye to the air would then suffice to destroy vision. 

51. Secretion of the Tears. — This secretion of the tears 
takes place at all times, during the night as well as the day ; 
but it is seldom noticed, except a person is under the influence 
of some strong mental emotion, when it is poured forth in ex- 
cess, so as to overflow the lids. Strong light or a rapid breeze 
will, among many other causes, excite the flow of the tears. 
That portion of this secretion not used in moistening the eye is 
carrieil off into the nose by a canal, called the 7iasal dud, situ- 
ated near the inner angle of the eye. This duct, shown in Fig. 
36, 2, is connected with each lid by delicate tubes, which are 
indicated by dotted lines in the figure ; the asterisk marks the 
little opening in the lower lid, by which the tears enter the 
nasal duct. By gently turning the inner part of that lid dow^n- 
ward, and looking in a mirror, this small "lachrymal point" may 
be seen in your own eye. In old people, these points become 
turned outwards, and do not conduct the tears to the nasal 
cavity, so causing an overflow of tears upon the face. 

52. Thus we observe that the gland which forms the tears is 
placed at the outer part of the eye, while their means of exit is 
at the inner angle of the eye ; which fact renders it necessary 
for this watery fluid to pass over the surface of the eyeball 
before it can escape. This arrangement cannot be accidental, 
but evinces design, for it thus secures the perfect lubrication of 
the surface of the eye, and cleanses it from the smaller particles 
of dust which may enter it, in spite of the vigilance of the lids 
and lashes. The act of winking, which is generally unconsci- 
ously performed, and which takes place six or more times in a 



150 THE SPECIAL SENSES. 

minute, assists this passage of the tears across the eye, and is 
especially frequent when the secretion is most abundant. 

53. The Eyeball. — The remarkable optical instrument called 
the eyeball, or the globe of the eye, upon which sight depends, 
is, as the name indicates, spherical in shape. It is not a perfect 
sphere, since the front part projects somewhat beyond the rest, 
and at the posterior part the optic nerve (Fig. 37, N) is united 
to it, resembling the junction of the stem with a fruit. In its 
long diameter, that is, from side to side, it measures a little 
more than an inch ; in other directions it is rather less than an 
inch. In structure, the ball of the eye is firm, and may be felt 
by pressing the fingers over the closed lids. 

54. The eyeball is composed chiefly of three internal, trans- 
sparent media, called humors; and three investing coats, or 
tunics. The former are the aqueous liumoi\ Fig. 37, A, the 
crystalline lens L, and the vitreous humor V. Of these the lens 
alone is solid. The three coats of the eyeball are called the 
sclerotic S, the choroid Ch, and the retina R. This arrangement 
exists in respect to five-sixths of the globe of the eye, but in the 
anterior one-sixth, these coats are replaced by the cornea C, 
which is thin and transparent, so that the rays of light pass 
freely through it, as through a clear window-pane. 

55. The Cornea in shape is circular and prominent, resembling 
a miniature watch-glass, about -^ of an inch thick. In structure, 
it resembles horn (as the name signifies), or the nail of the finger, 
and is destitute of blood-vessels. The Sclerotic (from scleros, 
hard) is composed of dense, white fibrous tissue, and gives to the 
eyeball its firmness of figure and its white color ; in front, it con- 
stitutes the part commonly called "the white of the eye." 

56. The Choroid is the second or middle coat of the eyeball, 
and lies closely attached to the inner surface of the sclerotic. 
Unlike the latter coat, its structure is soft and tender, it is dark 
in color, and possesses a great abundance of blood-vessels. Its 
dark color is due to a layer of dark brown or chocolate-colored 
cells spread out over its inner surface. This dark layer serves 



THE SPECIAL SENSES. 151 

to absorb the rays of liglit after they have traversed the trans- 
parent striirctiires in front of it ; if the rays were reflected from 
side to side witliin the eye, instead of being thus absorbed, con- 
fused vision would result from the multitude of images which 
would be impressed upon the optic nerve. 

57. The Iris. — Continuous with the choroid, in the front 
part of the globe of the eye, is a thin, circular curtain, which 
occasions the brown, blue, or gray color of the eye in different 
individuals. On account of the varieties of its color, this mem- 
brane has received the name Iris, which is the Greek word for 
"rainbow" (See Fig. 37, I). A front view of it is shown in 
Fig. 36. The iris is pierced in its centre by a round opening, 
called the impil (P), which is constantly varying in size. In 
olden times it was spoken of as the "apple of the eye." The 
hinder surface of the iris has a layer of dark coloring matter 
resembling that of the choroid. The iris is a muscular organ, 
and contains two distinct sets of fibres ; one of which is circular, 
while the other radiates outward from the pupil. The action 
of these sets of fibres regulates the size of the pupil ; for when 
the circular set acts, the pupil contracts, and when the other 
set acts, the opening expands. Their action is involuntary, and 
depends on the reflex system of nerves, which causes the con- 
traction of the pupil when a strong light falls upon the eye, 
and its expansion when the illumination is feeble. 

58. The iris, accordingly, serves a very useful purpose in regu- 
lating the admission of light to the eye. It, however, does not 
act instantaneously ; and hence, when we pass quickly from a 
dark room into the bright sunlight, the vision is at first con- 
fused by the glare of light, but as soon as the pupil contracts, 
the ability to see becomes perfect. On the other hand, when 
we enter a dark apartment, such as a cellar, for a short time wc 
can see nothing clearly ; but as soon as the pupil expands and 
admits more light, we are enabled to distinguish the surround- 
ing objects. Animals of the cat species, and others which prowl 
around after nightfall, are enabUed to see in the dark by having 



152 THE SPECIAL SENSES. , 

tke iris very dilatable. The size of the pupil affects the lustre 
of the eye. "N^Tien it is large, as it usually is during youth, the 
eye appears clear and brilliant ; while in old age the pupil is 
small and the eye is dull. 

59. The Retina constitutes the third and inner coat of the 
globe of the eye. This, the important part of the eye that is 
sensitive to light, is a kind of nervous membrane, formed by 
the expansion of the optic nerve. Its texture is soft, smooth, 
and very thin ; it is translucent and of a grayish- white color. 
It is sensitive to light alone ; and if any form of mechanical 
irritation be applied to it, the sensations of touch and pain are 
not experienced, but flashes of fire, sparks, and other luminous 
appearances are perceived. Too intense light occasions a feel- 
ing of pain, but it is of a peculiar kind, and is termed " daz- 
zHng." 

60. Impressions made upon the retina are not at once lost, 
but remain a measurable length of time, and then graduall}^ fade 
away. Thus, a bright light or color, gazed at intently, can- 
not be immediately dismissed from sight by closing or turning 
away the eyes. A stick lighted at one end, if whirled around 
rapidly in the dark, presents the appearance of an unbroken 
luminous ring ; and the spokes of a rapidly revolving carriage- 
wheel seem to be merged into a plane surface. If an object 
move too rapidly to produce this sort of lasting impression, it is 
invisible, as in the case of a cannon-ball passing through the air 
in front of us. 

61. If a card, painted with two primary colors — as red and 
yeUow — be made to rotate swiftly, the eye perceives neither of 
them distinctly ; but the card appears painted with their second- 
ary color — orange. The average duration of retinal images is 
estimated at one-eighth of a second; and it is because they 
thus endure, that the act of winking, which takes place so fre- 
quently, but so quickly, is not noticed and does not interrupt 
the vision. The retina is e isily fatigued or deprived of its 
sensibility. After looking steadfastly at a bright light, or at a 



THE SPECIAL SENSES. 153 

white object on a black ground, a dark spot, corresponding in 
shape to the bright object, presents itself in whatever direction 
we look. This spot passes away as the retina resumes its 
activity. In some persons the retina is incapable of distinguish- 
ing different colors, when they are said to be affected with " color- 
blindness." Thus, red and green may appear alike, and then a 
cherry-tree, full of ripe fruit, will seem of the same color in 
every part. Railroad accidents have occurred because the 
engineer of the train, who was color-blind, has mistaken the 
color of a signal. 

62. The Crystalline Lens. — Across the front of the eye, 
just behind the iris, is situated the Crystalline lens, enclosed 
within its o^vn capsule. It is supported in its place partly by a 
delicate circular ligament, and partly by the pressure of adjacent 
structures. It is colorless and perfectly transparent, and has a 
firm but elastic texture. In shape it is double-convex, and 
may be rudely compared to a small lemon-drop. It is only one- 
fourth of an inch thick. 

63. When this little body becomes opaque, and no longer 
affords free passage to the rays of light, as often happens with 
the advance of age, an affection termed " cataract " is produced. 
Between the crystalline lens and the cornea is a small space 
vv^hich contains the aqueous humor (See Fig. 37, A). This 
humor consists of five or six drops of a clear, colorless liquid 
very much like water, as its name implies. That part of the 
globe of the eye lying behind the lens is occupied by the vitreous 
humor, so called from its fancied resemblance to melted glass 
(Fig. 37, V). This humor is a transparent, jelly-like mass, 
enclosed within an exceedingly thin membrane, and constitutes 
fully two-thirds of the bulk of the eyeball. 

64. The Uses of the Crystalline Lens. — A convex lens 
has the property of converging the rays of light which pass 
through it ; and the point at which it causes them to meet is 
termed its focus. If a lens of this description, such as a magnify- 
ing or bur. ling-glass, be held in front of an open window, in 



154 THE SPECIAL SENSES. 

such a position as to allow its focus to fall upon a piece of 
paper, it will be found to depict upon the paper a miniature 
image of the scene outside of the window. It will be further 
noticed that the image is inverted, or upside down, and that 
the paper at the place upon which the image is thrown is much 
brighter than any other part. All the transparent structures of 
the eye, but especially the crystalline lens, operate upon the 



Fig. 38.— The Retikal Image 

retina, as the convex lens acts upon the paper ; that is, they 
paint upon the retina a bright inverted miniature of the objects 
that appear in front of the eye (Fig. 38). 

65. The form and structure of the crystalline lens endow it 
with a remarkable degree of refractive power, and enable it to 
converge all the rays of light that enter it through the pupil, to 
a focus exactly at the surface of the retina. AMien this lens is 
removed from the eye, as is frequently done for the cure of 
cataract, it is found that the rays of light then have their focus 
three-eighths of an inch behind the retina ; that the image is 
four times larger than in the healthy eye, that it is less brilliant^ 
and that its outline is very indistinct. From this we learn that 
one of the uses of the crystalline lens is to make the retinal 
image bright and sharply defined, at the same time that it 
reduces its size. Indeed, the small size of the image is a great 
advantage, as it enables the limited surface of the retina to re- 
ceive, at a glance, impressions from a considerable field of vision. 



J 



THE SPECIAL SENSES. 155 

66. As the image upon the retina is inverted, how does the 
mind perceive the object in its true, erect position ? Many ex- 
planations haA^e been advanced, but the simplest and most 
satisfactory appears to be found in the fact that the retina ob- 
serves no difference, so to speak, between the right and left or 
the upper and lower positions of objects. Consequently, our 
knowledge of the relative location of external objects must be 
obtained from some other source than the retina. The probable 
source of this knowledge is the habitual comparison of those 
objects with the position of our own bodies : thus, to see an 
elevated object, we know we must raise tlie head and eyes ; 
and to see one at our right hand, we must turn the head and 
eyes to the right. 

67. Long-sight or Hyperopia, and Short-sight op Myopia. 
The eye is not in all cases perfectly formed. For example, per- 
sons may from birth have the cornea too prominent or too flat, 
or the lens may be too thick or too thin. In either of these 
conditions sight will be more or less defective from the first, 




Fig. 39.— The Different Shapes of the Globe of the Eye, 

N, The Natural Eye. M, The Short-sighted Eye. 

H, The Long-sighted Eye. S, Parallel Rays from the Sun 

and the defect will not tend to disappear as life advances. The 
most common imperfection, however, is in the shape of the 
globe ; which may be short (Fig. 39, H), as compared with the 
natural eye, N, or it may be too long, M. 

68. When the globe is short, objects can only be clearly 
seen that are at a distance, and the condition of the vision is 
known as " long-sight," or hyperopia. It will be observed, by 



156 THE SPECIAL SENSES. 

reference to Fig. 39, that the focus of the rays of light would 
fall behind the retina of this eye. When the globe is too long, 
objects can only be clearly seen that are very near to the eye ; 
and the condition resulting from this defect is termed " short- 
sight," or myopia. The focus of the rays of light is, in this 
case, formed in the interior of the eye in front of the retina. 




Fig. 40. — The Function of Accommodation. 

The right half of the diagram shows the eye at rest. Tlie left half shows the lens 
accommodated for near vision. 

69. The Function of Accommodation.— If, after looking 
through an opera-glass at a very distant object, it is desired to 
view another nearer at hand, it will be found impossible to ob- 
tain a clear vision of the second object unless the adjustment of 
the instrument is altered ; which is effected by means of the 
screw. If an object, like the end of a pencil, be held near the 
eye, in a line with another object at the other side of the room, 
or out of the window, and the eye be fixed first upon one and 
then upon the other, it wdll be found that when the pencil is 
clearly seen, the further object is indistinct; and when the 
latter is seen clearly, the pencil appears indistinct ; and that it 
is impossible to see both clearly at the same time. Accordingly, 
the eye must have the capacity of adjusting itself to distances, 
which is in some manner comparable to the action of the screw 
of the opera-glass. 

70. This, which has been called the function of accommoda- 



THE SPECIAL SENSES. 157 

tion, is one of the most admirable of all the powers of the eye, 
and is exercised by the crystalline lens. It consists essentially 
in a change in the curvature of the front surface of the lens, 
partly through its own elasticity, and partly through the action 
of the ciliary muscle. AMien the eye is at rest, that is, when 
accommodated for a distant object, the lens is flatter and its 
curvature diminished (see Fig. 40) ; but when strongly accom- 
modated for near vision the lens becomes thicker, its curvature 
increases, and the image on the retina is made more sharp and 
distinct. Since a strong light is not required in viewing near 
objects, the pupil contracts, as is shown in the left-hand half of 
the diagram. 

71. Old-sight, op Presbyopia. — But this marvellously beau- 
tiful mechanism becomes worn with use ; or, more strictly 
speaking, the lens, like other structures of the body, becomes 
harder with the approach of old age. The material composing 
the lens becomes less elastic, the power to increase its curvature 
is gradually lost, and, as a consequence, the person is obliged to 
hold the book further away when reading, and to seek a stronger 
light. In a word, the function of accommodation begins to fail, 
and is about the first evidence that marks the decline of life. 
By looking at the last preceding diagram, and remembering that 
the increased curvature of the lens cannot take place, it will be 
at once understood why old-sight is benefited in near vision by 
the convex lens, such as the spectacles of old people contain. 
It acts as a substitute for the deficiency of the crystalline 
lens. 

72. The Sense of Hearing. — Sound. — Hearing is the special 
sense by means of which we are made acquainted with sound. 
What is sound ? It is an impression made upon the organs of 
hearing, by the vibrations of elastic bodies. This impression is 
commoidy propagated by means of the air, which is thrown into 
delicate undulations, in all directions from the vibrating sub- 
stance. Wlien a stone is thrown into smooth water, a wave of 
circular form is set in motion, from the point where the stone 



158 THE SPECIAL SENSES. 

struck, wliicli constantl}^ increases in size and diniinislies in 
force, as it advances. 

73. Somewhat resembling this, is the undulation, or sound- 
wave, which is imparted by a sonorous vibration to the sur- 
rounding atmosphere. The rate of motion of this spherical 
wave of air is about 1050 feet per second, or one mile in five 
seconds. In water, sound travels four times as fast as in air, 
and still more rapidly through solid bodies ; along an iron rod, 
its velocity is equal to two miles per second. 

74. The earth, likewise, is a good conductor of sound. It 
is said that the Indian of our western prairies can, by listen- 
ing at the surface of the ground, hear the advance of a troop of 
cavalry, while they are still out of sight, and can even discrimi- 
nate between their tread and that of a herd of buffaloes. Solid 
substances also convey sounds with greater power than air. If 
the ear be pressed against one end of a long beam, the scratch- 
ing of a pin at the other extremity may be distinctly heard, 
which will not be at all audible when the ear is removed from 
the beam. Although air is not the best medium for conveying 
sound, it is necessary for its production. Sound cannot be pro- 
duced in a vacuum, as is shown by ringing a bell in the ex- 
hausted receiver of an air-pump, for it is then entirely inaudible. 
But let the air be readmitted gradually, then the tones become 
more and more distinct, and when the receiver is again full of 
air, they will be as clear as usual. 

75. All sonorous bodies do not vibrate with the same degree 
of rapidity, and upon this fact depends the pitch of the sounds 
that they respectively produce. The more frequent the number 
of vibrations within a given time, the higher will be the pitch ; 
and the fewer their number, the lower or graver will it be. 
!Row, the rate of the successive vibrations of different notes 
has been measured, and it has thus been found that if they are 
less than sixteen in a second, no sound is audible ; while if they 
exceed 60,000 per second tlie sound is very faint, and is painful 
to the ear. The extreme limit of the. capacity of the human 



THE SPECIAL SENSES. 



159 



ear may be considered as included between these points ; but 
the sounds which we ordinarily hear are embraced between 100 
and 3,000 vibrations per second. 

76. The eai\ which is the proper organ of hearing, is the 
most complicated of all the structures that are employed in the 
reception of external impressions. The parts of which it is 
composed are numerous, and some of them are extremely small 
and delicate. Nearly all these parts are located in an irregularly 
shaped cavity hollowed out in the temporal, or " temple," bone 




Fig. 41.— The Ear and its Different Parts. 

A, Diagram of the Ear. 

a, b, External Ear. d, Middle Ear. 

c, Membrane tynipani. e, Internal Ear. 

B to B'", Bones of the Middle Ear (magnified). 

C, The Labyrinths, or Internal Ear (highly magnified). 

of each side of the head. That part of the bone in which the 
auditory cavity is placed has the densest structure of all bones 
of the body, and has therefore been called the " petrous," or 
rocky part of the temporal bone. In studying the ear, it is 
necessary to consider it as divided into three portions, which 
are called, from their relative positions, the external ear, the 
middle ear, and the internal ear. (In the diagram, Fig. 41, A, 
the first is not shaded, the second is lightly shaded, and the last 



has a dark background. 



160 THE SPECIAL SENSES. 

77. The External Ear. — The external portion of the organ 
of hearing, designated in Fig. 41, A, includes, first, that outer 
part (a), which is commonly spoken of as " the ear," but which 
in fact is only the portal of that organ ; and, secondly, the 
auditory canal (h). The former consists of a flat flexible piece 
of cartilage, projecting slightly from the side of the head, 
attached to it by ligaments, and supplied with a few weak 
muscles. ' Its surface is uneven, and curiously curved, and 
from its resemblance to a shell, it has been called the concha. 
It probably serves to collect sounds, and to give them an inward 
direction ; although its removal is said not to impair the acute- 
ness of hearing more than a few days. 

78. The auditory caned Fig. 41, A, h), which is continuous 
with the outer opening of the ear, is a passage, an inch and a 
quarter in length, its inner extremity being bounded by a closely- 
fitting, circular membrane. This canal is of oval form, is 
directed forward and inward, and is slightly curved; so that 
the inner end is ordinarily concealed from view. The pouch of 
the skin which lines this passage is smooth and thin, especially 
at the lower end, where it covers the membrane just men- 
tioned. 

79. As in the case of the nostrils, a number of small, stiff 
hairs garnish the margin of the auditory canal, and guard it, to 
some extent, against the entrance of insects and other foreign 
objects. The skin, too, covering its outer half, is furnished 
with a belt of little glands which secrete a yellow, bitter sub- 
stance, called " ear-wax," which is especially obnoxious to small 
insects. As the outer layer of this wax-like material loses its 
useful properties, it becomes dry, and falls out of the ear in the 
form of minute, thin scales, a fresh supply being furnished 
from the little glands beneath. In its form, the auditory canal 
resembles the tube of an ear- trumpet, and serves to convey the 
waves of sound to the middle portion of the ear. 

80. The Middle Ear, op Tympanum. — The middle ear is 
a small cavity, or chamber, of irregular shape, about one-fourth 



THE SPECIAL SENSES. 161 

of an inch across from side to side, and half an inch long (see 
Fig, 41, A, d). From the peculiar arrangement of its various 
parts it has very properly been called the tympanum, or the 
" drum of the ear." The middle ear, like the external canal, 
contains air. 

81. The circular membrane, already mentioned as closing the 
auditory canal, is the partition which separates the middle from 
the external ear, and is called the memhrana tympani (c), and 
may be considered as the outer head of the drum of the ear. It 
is sometimes itself spoken of as the '' drum," but this is incor- 
rect ; since a drum is not a membrane, but is the hollow space 
across which the membrane is stretched. This membranous 
drum-head is very tense and elastic, and so thin as to be almost 
transparent ; its margin is fastened into a circular groove in the 
adjacent bone. Each wave of sound that touches this delicate 
membrane causes it to vibrate, and it, in turn, excites move- 
ments in the parts beyond. 

82. Within the tympanum is arranged a chain of remarkable 
" little bones," or ossicles. They are chiefly three in number, 
and from their peculiar shapes bear the following names : mal- 
leus, or the mallet ; incus, or the anvil ; and stapes, or the 
stirrup. A fourth, the smallest bone in the body, in early life 
intervenes between the incus and stapes, but at a later period 
it becomes a part of the incus. It is called the orbicular bone. 
Small as are these ossicles — and they, together, weigh only a 
few grains — they have their little muscles, cartilages, and blood- 
vessels, as perfectly arranged as the larger bones of the body. 
One end of the chain of ossicles, the mallet, is attached to the 
membrane of the tympanum, or outer drum-head, while the 
other end, the stirrup, is firmly joined by its foot-piece to a 
membrane in the opposite side of the cavity. The chain, 
accordingly, hangs suspended across the drum between the two 
membranes ; and when the outer one vibrates under the influ- 
ence of the sound-wave, the chain swings inward and transmits 
the vibration to the entrance of the inner ear. 



162 



THE SPECIAL SENSES. 



83. The musical instrument, tlie drum, is not complete if the 
air within be perfectly confined ; we therefore find in all instru- 
ments of this kind a small opening in the side, through which 
air may pass freely. The tympanum, or drum of the ear, in like 
manner has an opening by means of which it communicates 
freely with the external air. This opening is a narrow canal, 
about an inch and a half long, called the Eustachian tube, after 
the name of its discoverer, Eustachius. 

84. The course of this passage is indicated in Fig. 42, I, 




Fig. 42.— Section of the Right Ear. 



A, The Concha. 

B, Auditory Canal, 

C, Membrane of the Drum, 

(the lower half.) 

D, A small muscle. 



E, Incus, or Anvil. 
M, Malleus, or Mallet. 
I, Eustachian Tube. 
G, Semicircular Canals 
H, Cochlea, or snail's shell. 



directed downward and inward : its other extremity opens into 
the upper part of the throat. The passage itself is ordinarily 
closed, but whenever the act of swallowing or gaping takes 
place, the orifice in the throat is stretched open, and the air of 
the cavity of the tympanum may then be renewed. 



Jj 



THE SPECIAL SENSES. 163 

85. The Eustachian tube serves, also, as an escape-pipe for the 
fluids which form within the middle ear ; and hence, when its 
lining membrane becomes thickened, in consequence of a cold, 
or sore throat, and the passage is thus more or less choked up, 
the fluids are unable to escape as usual, and therefore accumu- 
late within the ear. A^^len this takes place, the vibrations of 
the membrane are interfered with ; the sounds heard appear 
muffled and indistinct ; and a temporary difficulty of hearing, 
which is known as " throat-deafness," is the result. This result 
resembles the eff'ect produced by interrupting the vibrations of 
a sonorous body, such as all are familiar with ; if the finger be 
placed upon a piano-string or bell when it is struck, the proper 
soimd is no longer fully and clearly emitted. But the primary 
use of this tube is to afford a free communication between the 
middle ear and the external atmosphere, and thus secure an 
equal pressure upon both sides of the membrane of the drum 
of the ear, however the density of the atmosphere may vary. 
If from undue tension of the membranes, pain is experienced 
in the ears, when ascending into a rare atmosphere, as in a bal- 
loon, or descending into a dense one, as in a diving-bell, it 
may be relieved by repeating the act of swallowing, from time 
to time, in order that the inner and outer pressure may thus 
be promptly equalized. 

86. The Internal Ear, op Labyrinth. — The most essential 
part of the organ of hearing is the distribution of the auditory 
nerve. This is found within the cavity of the internal ear, 
which, from its exceedingly winding shape, hag been termed 
the labyrinth (see Fig. 42, C). This cavity is hollowed out in 
dense bone, and consists of three parts ; the vestibule (a), or 
ante-chamber, which is connected with the other two; the 
cochlea (b), or snail's shell ; and the three semicircular canals (c). 
The manner in which the nerve of hearing is distributed is 
remarkable, and is peculiar to this nerve. In the vestibule and 
the canals its fibres are spread out over the inner surface, not of 
the bony cavity but of a membranous bag, which conforms to 



164 THE SPECIAL SENSES. 

and partially fills that caAdty ; and which floats in it, being 
both filled and suiTounded with a clear, limpid fluid. 

87. A singular addition to the mechanism of hearing is ob- 
served within this membranous bag of the labyrinth. This 
consists of two small oval ear-stones, and a quantity of fine 
powder of a calcareous nature, Avhich is called "ear-sand." 
When examined under the microscope, these sandy particles 
are seen to lie scattered upon and among the delicate filaments 
of the auditory nerve ; and it is probable, that, as the tremulous 
sound-wave traverses the fluid of the vestibule, the sand rises 
and falls upon the nerve filaments, and thus intensifies the 
sonorous impression. 

88. In the cochlea, or snail's shell, which contains the fluid, 
but no membrane, the nerve branches upon a spiral shelf. As 
many as three thousand nerve fibres of difi'erent lengths have 
been counted therein ; which, it has been thought, form the 
grand, yet minutely small key-board, upDn which strike all the 
musical tones that are destined to be conveyed to the brain. 
The vestibule, it is also supposed, takes notice of noise as dis- 
tinguished from musical sounds ; while the office of the semi- 
circular canals is, in part at least, to prevent internal echoes, or 
reverberations. 

89. The vestibule communicates with the chain of bones of 
the middle ear by means of a small opening, called the •' oval 
window," or fenestra ovalis. Across this window is stretched 
the membrane, which has already been alluded to as being 
joined to the stirrup-bone of the middle ear. Through this 
window, then, the sound-wave, which traverses the external and 
middle ear, arrives at last at the labyrinth. The limpid fluid 
which the latter contains, and which bathes the terminal fibres 
of the nerve of hearing, is thus agitated, the nerve-fibres are 
excited, and a sonorous impression is conducted to the brain, or, 
as we say, a sound is heard. 

90. Protection of the Sense of Heaping. — From what has 
been seen of the complicated parts which compose the organ of 



THE SPECIAL SENSES. 165 

hearing, it is evident that while many of them possess an 
exquisite delicacy of structure, Nature has well and amply pro- 
vided for their protection. We have observed the concealed 
situation of the most important parts of the mechanism of the 
ear, the length of its cavity, its partitions, the hardness of its 
walls, and its communication with the atmosphere ; all these 
provisions rendering unnecessary any supervision or care on our 
part in reference to the interior of the ear. But in respect to 
its external parts, which are under our control and within the 
reach of harm, it is otherwise. We may both observe the 
dangers which threaten them, and learn the means necessary to 
protect them. 

91. One source of danger to the hearing consists in lowering 
the temperature of the ear, especially by the introduction of 
cold water into the auditory canal. Every one is familiar with 
the unpleasant sensation pi distension and the confusion of 
sounds which accompany the filling of the ear with water when 
bathing : the weight of the water within it really distends the 
membrane, and the cold chills the adjacent sensitive parts. It 
is not surprising, therefore, that the frequent introduction of 
cold water and its continued presence in the ear enfeeble the 
sense of hearing. Care should be taken to remove water from 
the ear after bathing, by holding the head on one side, and, at 
the same time, slightly expanding the outer orifice, so that the 
fluid may run out. For a like reason, the hair about the ears 
should not be allowed to remain wet, but should be thoroughly 
dried as soon as possible. 

92. Caution. — It may be stated as a general rule, to which there 
are but few exceptions, that no cold liquid should ever be allowed 
to enter the ear. When a wash or injection is rendered neces- 
sary, it should always be warmed before use. The introduction 
of cold air is likewise hurtful, especially when it pours through 
a crevice directly into the ear, as it may often do through the 
broken or partially closed window of a car. The avoidance of 
this evil gives rise to another almost as great ; namely, the in- 



166 THE SPECIAL SENSES. 

troduction of cotton or other soft substances into the ear to 
prevent it from " catching cold." This kind of protection tends 
to make the part unnaturally susceptible to changes of tempera- 
ture, and its security seems to demand the continued presence 
of the "warm" covering. As a consequence of its presence, 
sounds are not naturally conveyed, and the sensitiveness of the 
nerve of hearing is gradually impaired. 

93. The chief source of injury, however, to the ear is from 
the introduction of solid substances into the auditory canal, 
with the design of removing insects or other foreign objects 
that have foimd their way into the ear ; or with the design of 
scraping out the ear-wax. For displacing a foreign object, it is 
usually sufficient to s^Tinge the ear gently with warm water, 
the head being so held that the fluid easily escapes. If a live 
insect has gained entrance to the ear, it may first be suffocated 
by pouring a little oil upon it, and afterward removed by 
syringeing the ear as just mentioned. 

94. The removal of ear-wax is generally unnecessary ; for, as 
we have before seen, ISTature provides that the excess of it shall 
become dry, and then spontaneously fall out in the form of fine 
scales. The danger from the introduction of solid implements 
into the outer ear is chiefly found in the fact that the mem- 
brane which lies at the bottom of it is very fragile, and that 
any injury of it is liable to be permanent, and to impair per- 
manently the hearing of the injured ear. 



SPECIAL SENSES. 167 



QUESTIONS FOR TOPICAL REVIEW. 

PAGE 

1. What do you vmderstand by sensations ? 130 

2. State what is said of their variety 131 

3. Wliat is meant by general sensibility ?. 132 

4. Discuss the sensation of pain 133 

5. Of what healthful importance is pain ? 133 

6. What is ineant by special sensation, and what other names has it according 

to its occurrence ? 134 

7. What is said of the organs of touch ? 135 

8. What is the special importance of touch ? 135 

9. State what you know of the delicacy of touch 137 

10. To Avhat do the sensations of temperature and weight refer ? 138 

11. Describe the organs concerned in taste , 138 

12. Give a general explanation of the sense 139 

13. What relation does taste bear to other senses 140 

14. What is the peculiarity of taste ? • 141 

15. Explain how we can smell , 142 

16. Show the function of the olfactory nerve 143 

17. Why is the sense of smell so important to health ? 144 

18. Repeat what you know of the sense of sight 144 

19. How does light affect the optic nerve ? 145 

20. What is said of the eye and its uses 146 

21. Wliat office do the orbits hold ? 146 

22. Describe the eyelids 147 

23. Illustrate a vertical section of the eye showing the coats 148 

24. Of what use are the tears ? 149 

25. How are the tears secreted, and what happens when they appear on the eyeball ? 149 

26. State what you know of the eyeball 150 

27. Describe the cornea 150 

28. Of what importance is the choroid coat ? 150 

29. What is said of the iris and its purpose ? 151 

30. What is the nature of the retina, and what purpose does it serve ? 152 

31. Illustrate the use of the crystalline lens 153 

32. What properties has the lens ? 153 

33. What do you understand by hyperopia? 155 

34. What is meant by myopia? 155 

35. Illustrate the function of accommodation 156 

36. Explain the loss of sight in old age 157 

37. What is soimd, and how do we hear ? 157 

38. What are the parts concerned in hearing ? 159 

39. Describe the external ear 100 

40. What is the office of the auditory canal ? 160 

41. Explain the mechanism of the tympanum 160 

42. What purpose does the Eustachian tube serve ? 162 

43. To what is "throat deafness " due ? 163 

44. Explain the construction of the labyrinth 163 



CHAPTER X. 

The Voice. 

Voice and Speech — The Larynx, or the Organ of the Voice — 
The Vocal Cords — The Laryngoscope — The Production 
of the Voice — The Use of the Tongue — The different 
Varieties of Voice — The Change of Voice — Its Compass 
— Purity of Tone — Ventriloquy. 

1. Voice and Speech.- — In conunoii with the majority of the 
nobler animals, man possesses the power of uttering sounds, 
which are employed as a means of communication and expres- 
sion. In man, these soimds constitute the voice; in the 
animals, they are designated as the cry. The song of the bird 
is a modification of its cry, which is rendered possible from the 
fact that its respiratory function is remarkably active. The 
sounds of the animals are generally, but not always, produced 
by means of their breathing organs. Among the insects, they 
are sometimes produced by the extremely rapid vibrations of 
the wings in the act of flight, as in the case of the mosquito ; 
or- they are produced by the rubbing together of hard portions 
of the external covering of the body, as in the cricket. 

2. But man alone possesses the faculty of speech, or the 
power to use articulate sounds in the expression of ideas, and 
in the communication of mind with mind. Speech is thus an 
evidence of the superior endowment of man, and involves the 
cidture of the intellect. An idiot, while he may have complete 
vocal organs and full power of uttering sounds or cries, is 
entirely incapable of speech ; and, as a rule, the excellence of 



THE VOICE. 169 

the language of any people Avill be found to be proportional to 
tlieir development of brain. Man, liowever, is not the only 
being that has the power to form articulate sounds, for the 
parrot and the raven may also be taught to speak by rote ; but 
man alone attaches meaning to the words and phrases he em- 
ploys. 

3. Relation of Speech to Hearing. — Speech is intimately 
related to the sense of hearing. A child born deaf is, of neces- 
sity, dumb also ; not because the organs of speech are imper- 
fect, for he can utter cries and may be taught to speak, and 
even to converse in a rude and harsh kind of language ; but 
because he can form no accurate notion of sound. And a per- 
son, whose hearing is not delicate, or as it is commonly ex- 
pressed, who " has no ear for music," cannot sing correctly. A 
person who has impaired hearing commonly talks in an un- 
naturally loud and monotonous voice. These examples show 
the necessary relation of intelligence and the sense of hear' 
ing with that form of articulate voice, which is termed speech. 

4. The Organ of the Voice. — The essential organ of the 
voice is the Larynx. This has been previously alluded to in 
its relation to the function of respiration ; and, in the chapter 
on that subject, are figured the front view of that organ (Fig. 
25), and its connection with the trachea, tongue, and other 
neighboring parts (Fig. 28). It is situated at the upper part of 
the neck, at the top of the trachea, or tube by which air passes 
into and out of the lungs. The framework of the larynx is 
composed of four cartilages, which render it at once very strong 
and sufficiently flexible to enable it to move according to the 
requirements of the voice. 

5. The names of the cartilages are (1) the thyroid, which is a 
broad thin plate, bent in the middle and placed in the central 
line of the front part of the neck, where it is known as the 
pomum Adami, or Adam's apple (Fig. 43, B), and where it 
may be felt moving up and down with each act of swallowing ; 
(2) the cricoid, which is shaped like a seal ring, with the broad 



170 



THE VOICE. 



part placed posteriorly (Fig. 43, E). At 
the top of the cricoid cartilage are 
situated the two small arytenoid carti- 
lages, the right one of which is shown 
in Fig. 43, C. These latter little organs 
are much more movable than the other 
two, and are very important in the pro- 
duction of the voice. They have a 
true ball and socket joint, and several 
small muscles which contract and relax 
with as perfect regularity and accuracy 
as any of the larger muscles of the body. 

6. The interior of the larynx is lined 
with a very sensitive mucous membrane, 
which is much more closely adherent to 
the parts beneath than is usually the 
case with membranes of this description. 
The epiglottis (A), consisting of a single 
leaf-shaped piece of cartilage, is attached 
to the front part of the larynx. It is 
elastic, easily moved, and fits accurately 
over the entrance to the air-passages 
below it. Its office is to guard these 
delicate passages and the lungs against 
the intrusion of food and other foreign 
articles, when the act of swallowing takes place 
in modifying the voice. 

7. The Vocal Cords. — Within the larynx, and stretched 
across it, from the thyroid cartilage in front to the arytenoid 
cartilages behind, are placed the two sets of folds, called the 
vocal cords. The upper of these, one on each side, are the 
false cords, which are comparatively fixed and inflexible. These 
are not at all essential to the formation of vocal sounds, for they 
have been injured, in those lower animals whose larynx re- 
sembles that of man, without materially affecting their charac- 




FiG. 43. 

Section of the Larvnx and 

Trachea. 

A, Tlie Epiglottis. 

B, The ThjToid Cartilage. 

C, Arytenoid Cartilage. 

D, Ventricle of the Larjaix. 

E, Cricoid Cartilage. 

F, Right Vocal Cord. 
H, The Trachea. 



It also assists 



THE VOICE. 



171 



cords (Fig. 43, F). They are composed of a highly elastic, 
though strong tissue, and are covered with a thin, tightly-fitting 
layer of mucous membrane. Their edges are smooth and sharply- 
defined, and when they meet, as they do in the formation of 
sounds, they exactly match each other. 

8. If one or both of these cords are injured or become dis- 
eased, voice and speech are weakened; or when the mucous 
membrane covering them becomes thickened, in consequence of 
a cold, the vocal sounds are rendered husky and indistinct. 
When an opening is made in the throat below the cords, as not 
infrequently happens in consequence of an attempt to commit 
suicide, voice is impossible except when the opening is closed 
by external pressure. 




Fig. 44. — A View of the Vocal Cords by Means of the Laryngoscope. 

9. The interval or space between the true cords of the voice 
is constantly varying, not only when their vocal function is in 
exercise, but also during the act of respiration. Every time 
the lungs are inflated, the space increases to make wide the 
entrance for the air ; and diminishes slightly during expiration. 
So that these little cords move gently to and fro in rhythm 
with the expansion and contraction of the chest in breathing. 
These movements and others may be seen to take place, if a 
small mirror attached to a long handle be placed back into the 
upper part of the throat ; the handle near the mirror must be 



172 THE VOICE. 

bent at an angle of 45°, so that we may look "around the 
corner/' so to speak, behind the tongue. The position which 
the minor must assume will be understood by reference to Fig. 
28. A view of what may be seen under favorable circum- 
stances, during tranquil inspiration is represented in Fig. 44. 
The vocal cords are there shown as narrow, white bands, on 
each side of the central opening, and since the image is inverted, 
the epiglottis appears uppermost. The rings partly seen through 
the opening belong to the trachea. This little mirror is the 
essential part of an instrument, which is called the laryngoscope, 
and, simple as it may seem, it is accounted one of the most 
valuable of the recently invented appliances of the medical 
art. 






Fig. 45.— The Different Positions of the Vocal Cords. 
A, The position during inspiration. B, In the formation of low notes. C, In the for- 
mation of high notes. 



10. The Production of the Voice. — During ordinary tran- 
quil breathing no sound is produced in the larynx, true vocal 
tones being formed only during forcible expiration, Avhen, by an 
effort of the will, the cords are brought close together, and are 
stretched so as to be very tense. The space between them is 
then reduced to a narrow slit, at times not more than yg-o of an 
inch in width ; and the column of expired air being forced 
through it causes the cords to vibrate rapidly, like the strings 
of a musical instrument. Tlius the voice is produced in its 
many varieties of tone and pitch ; its intensity, or loudness, 
depending chiefly upon the power exerted in expelling the air 
from the lungs. WTien the note is high, the space is dimin- 
ished both in length and width ; but when it is low, the space 



THE VOICE. 173 

is wider and longer (Fig. 45, B, C), and the number of vibra- 
tions is fewer within the same period of time. 

11. The personal quality of the voice, or that which enables 
us to recognize a person by his speech, is mainly due to the 
peculiar shape of the throat, nose, and mouth, and the resonance 
of the air contained witliin those cavities. The walls of the 
chest and the trachea take part in the resonance of the voice, 
the air within them vibrating at the same time with the parts 
above them. This may be tested by touching the throat or 
breast-bone, when a strong vocal effort is made. The teeth and 
the lips also are important, as is shown by the unnatural tones 
emitted by a person who has lost the former, or by one who is 
affected with the deformity known as "hare-lip." The tongue 
is useful, but not indispensable to speech ; the case of a woman 
is reported, from whom nearly the whole tongue had been torn 
out, but who could, nevertheless, speak distinctly and even 
sing. 

12. The Varieties of voice are said to be four in number; 
two, the bass and tenor, belonging to the male sex ; and two, 
the contralto or alto, and soprano, peculiar to the female. The 
baritone voice is the name given to a variety intervening be- 
tween the bass and tenor. In man, the voice is strong and 
deep ; in woman, soft and high. In infancy and early youth, 
the voice is the same in both sexes, being of the soprano variety : 
that of boys is both clear and loud, and being susceptible of 
considerable training, is highly prized in the choral services of 
the church and cathedral. At about fourteen years of age the 
voice is said to change ; that is, it becomes hoarse and unsteady 
by reason of the rapid growth of the larynx. In the case of 
the girl, the change is not very marked, except that the voice 
becomes stronger and has a wider compass ; but in the boy, the 
larynx nearly doubles its size in a single year, the vocal cords 
grow thicker, longer, and coarser, and the voice becomes mascu- 
line in character. During the progress of this change, the use 
of the voice in singing is injudicious. 



174 THE VOICE. 

13. The ordinary range of each of the four varieties of the 
voice is about two octaves ; but this is exceeeded in the case of 
several celebrated vocalists. Madame Parepa Rosa has a com- 
pass of three full octaves. '\^Tien the vocal organs have been 
subjected to careful training, and are brought under complete 
control of the Avill, the tension of the cords become exact, 
and their vibrations become exceedingly precise and true. 
Under these circumstances the voice is said to possess "purity" 
of tone, and can be heard at a great distance, and above a multi- 
tude of other sounds. The power of a pure voice to make itself 
heard was recently exemplified in a striking manner : at a 
musical festival held in an audience-room of extraordinary size, 
and amid an orchestra of a thousand instruments and a chorus 
of twelve thousand voices, the artist named above also sang ; 
yet such was the purity and strength of her voice that its notes 
could be clearly heard rising above the vast waves of sound 
produced by the full accompaniment of chorus and orchestra. 

14. Ventriloquism is a peculiar modification of natural speech, 
which consists in so managing the voice that words and sounds 
appear to issue, not from the person, but from some distant 
place, as from the chimney, cellar, or the interior of a chest. 
The ventriloquist not only seems to " throw his voice," as it is 
said, or simulates the sound as it usually appears at a distance 
with but little motion of the lips and face, but he imitates the 
voices of an infant and of a feeble old man, of a drunken man 
disputing with an exasperated wife, the broken language of a 
foreigner, the cry of an animal in distress, demonstrating that 
the performer must be proficient in the art of mimicry. Ven- 
triloquism was known to the ancient Romans and Greeks; and 
it is thought that the mysterious responses that were said to 
issue from the sacred trees and shrines of the oracles at Do- 
dona and Delphi, were really uttered by priests who had the 
power of producing this form of speech. 



THE VOICE. 175 



QUESTIONS FOR TOPICAL REVIE^A/". 

PAGE 

1. Define your understanding of voice and speech, showing their distinction 168 

2. Of what is speech an index? 168 

3. How is speech related to hearing? 169 

4. Name and describe the organs concerned in the voice 169 

5. What office have the cartilages ? 170 

6. Where and what is the epiglottis ? 170 

7. Say what you know of the vocal cords 171 

8. Upon what does the quality of the voice depend ? 173 

0. Give the statement regarding the varieties of the voice 173 

10. What is ventriloquism, and what mysteries does it help to explain ? 174 

11. What is the ordinary range of voice ? 174 



1"v 



APPEE"DIX 



Poisons and their Antidotes. 

Accidents from poisoning are of such frequent occurrence, that every- 
one should be able to administer the more common antidotes, until the 
services of a physician can he obtained. As many jioisons bear a close 
resemblance to articles in common use, no dangerous substance should be 
brought into the household without having the word poison plainly 
written or printed on the label ; and any package, box, or vial, without a 
label, should be at once destroyed, if the contents are not positively 
known. 

When a healthy person is taken severely and suddenly ill soon after 
some substance has been swalloived, we may suspect that he has been 
poisoned. In all cases where poison has been taken into the stomach, it 
should be quickly and thoroughly expelled by some active emetic, which 
can be speedily obtained. This may be accomplished by drinking a tum- 
blerful of warm water, containing either a tablespoonful of powdered 
mustard or of common salt, or two teaspoonfuls of powdered alum in two 
tablespoonfuls of syrup. When vomiting has already taken place, it 
should be maintained by copious draughts of warm water or mucilaginous 
drinks, such as gum-water or flaxseed tea, and tickling the throat with 
the finger until there is reason to believe that all the poisonous substance 
has been driven from the stomach. 



The following list embraces only the more common poisons, together 
with such antidotes as are usually at hand, to be used until the physician 
arrives. 

Acids. — Hydrochloric acid ; muriatic acid (spirits of salt) ; nitric 
acid (aqua fortis) ; sulphuric acid (oil of vitriol). 

Antidote. — An antidote should be given at once to neutralize the acid. 
Strong soapsuds is an efficient remedy, and can always be obtained. It 
should be followed by copious draughts of warm water or flaxseed tea. 
Chalk, magnesia, soda or saleratus (with water) or lime-water, are the 
best remedies. When sulphuric acid has been taken, water should be 



178 APPENDIX. 

given sparingly, because, when water unites with this acid, intense heat is 
produced. 

Oxalic acid. 

Antidote. — Oxalic acid resembles Epsom salts in appearance, and may 
easily be mistaken for it. The antidotes are magnesia, or chalk mixed 
with water. 

PrussiC Acid; oil of hitter almonda ; laurel ivater j cyanide of po- 
tassiiim (used in electrotyping). 

Antidote. — Cold douche to the spine. Chlorine water, or water of 
ammonia largely diluted, should be given, and the vapor arising from 
them inhaled. 

Alkalies and their Salts.— Ammonia (hartshorn), liquor or 
water of ammonia. Potassa : — caustic ijotash, strong lye, carbonate of 
potassa (pearlash), nitrate of iwtassa (saltpetre). 

Antidote. — Give the vegetable acids diluted, as weak vinegar, acetic, 
citric, or tartaric acids dissolved in water. Castor oil, linseed oil, and 
sweet oil may also be used ; they form soaps when mixed with the free 
alkalies, which they thus render harmless. The poisonous effects of salt- 
petre must be counteracted by taking mucilaginous drinks freely, so as to 
produce vomiting. 

Alcohol. — BraMdy, wine; all spirituous liquors. 

Antidote. — Give as an emetic ground mustard or tartar emetic. If 
the patient cannot swallow, introduce a stomach pump ; pour cold water 
on the head. 

Gases. — Chlorine, carbonic acid gas, carbonic oxide, fumes of burning 
charcoal, sulphuretted hydrogen, illuminating or coal-gas. 

Antidote. — For poisoning by chlorine, inhale, cautiously, ammonia 
(hartshorn). For the other gases, cold water should be poured upon the 
head, and stimulants cautiously administered ; artificial respiration. (See 
Marshall HalVs Ready Method, page 180.) 

Metals. — Antimony, tartar emetic, wine of antimony, etc. 

Antidote. — If vomiting has not occurred, it should be produced by 
tickling the throat with the finger or a feather, and the abundant use of 
warm water. Astringent infusions, such as common tea, oak bark, and 
solution of tannin, act as antidotes. 

Arsenic. — IVhite arsenic. Fowler's solution, fly -p)Owder, cobalt, Paris 
green, etc. 

Antidote. — Produce vomiting at once with a tablespoonful or two of 
powdered mustard in a glass of warm water, or with ipecac. The antidote 
is hydrated peroxide of iron. If Fowler's solution has been taken, lime- 
water must be given. 

Copper. — Acetate of copper (verdigris), sulp)hate of copper (blue 



APPENDIX. 179 

\dtriol), food cooked |in dirty copper vessels, or pickles made green by 
coj^jjer. 

Antidote. — Milk or white of eggs, with mucilaginous drinks (flaxseed 
tea, etc. ), should be freely given. 

Iron. — Sulphate of iron (copperas), etc. 

Antidote. — Carbonate of soda in some mucilaginous drink, or in water, 
is an excellent antidote. 

Lead. — Acetate of lead (sugar of lead), carbonate of lead (white lead), 
water kept in leaden pipes or vessels, food cooked in vessels glazed with 
lead. 

Antidote. — Induce vomiting with ground mustard or common salt in 
warm water. The antidote for soluble preparations of lead is Epsom salts ; 
for the insoluble forms, sulphuric acid largely diluted. 

Mercury. — Bichloride of mercury (corrosive sublimate), ammoniaicdj 
mercury (Avhite precipitate), red oxide of mercury (red precipitate), red 
sulphuret of mercury (vermilion). 

Antidote. ^— The white of eggs, or wheat flour beaten up with water 
and milk, are the best antidotes. 

SHyQV, —Nitrate of silver (lunar caustic). 

Antidote, — Give a teaspoonful of common salt in a tumbler of water. 
It decomposes the salts of silver and destroys their activity. 

Zinc. — Sulphate of zinc, etc. (white vitriol). 

Antidote. — The vomiting may be relieved by copious draughts 
of warm water. The antidote is carbonate of soda administered in 
water. 

WarCOtiC Poisons. — Op)ium (laudanum, paregoric, salts of mor- 
phia, Godfrey's cordial, Dalby's carminative, soothing syrup, cholera 
mixtures), aconite, belladonna, hemlock, stramonium, digitalis, tobacco, 
hyosciamus, mix vomica, strychnine. 

Antidote. — Empty the stomach by the most active emetics, as 
mustard, alum, or sulphate of zinc. The patient should be kept in 
motion, and cold water dashed on the head and shoulders. Strong coffee 
must be given. The physician will use the stomach pump and electricity. 
In poisoning by nux vomica or strychnine, etc. , chloroform or ether should 
be inhaled to quiet the spasms. 

Irritant Vegetable 'Boisons.—Croton oil, oil of savine, p)oke, 
oil of tansy, etc. 

Antidote.— If vomiting has taken place, it may be rendered easier by 
copious draughts of warm water. But if symptoms of insensibility have 
come on Mdthout vomiting, it ought to be immediately excited hy ground 
mustard mixed with warm water, or some other active emetic, and after its 
operation an active purgative should be given. After expelling as much of 



180 APPENDIX. 

the i)oison as possible, strong coffee or vinegar and water may be given 
with advantage. 

Poisonous Fish. — Conger eel, mussels, crabs, etc. 

Antidote. ^Evacuate, as soon as possible, the contents of the stomach 
and bowels by emetics (ground mustard mixed with warm water or pow- 
dered alum), and castor oil, drinking freely at the same time of vinegar 
and water. Ether, -v^ith a few drops of laudanum mixed with sugar and 
water, may afterward be taken freely. 

Poisonous Serpents.— Antidote.— A ligature or handkerchief 
should be applied moderately tight above the bite, and a cupping-glass 
over the wound. The patient should drink freely of alcoholic stimulants 
containing a small quantity of ammonia. The physician may inject 
ammonia into the veins. 

Poisonous Insects. — Stiwjs of scotyion, hornet, wasp, bee, etc. 

Antidote, — A piece of rag moistened with a solution of carbolic acid 
may be kept on the affected part until the pain is relieved ; and a few 
drops of carbolic acid may be given frequently in a little water. The 
sting may be removed by making strong pressure around it mth the barrel 
of a small watch-key. 

Drown ing^. 

Marshall Hall's "Ready Method" of treatment in asphyxia from 
drowning, chloroform, coal-gas, etc. 

1st. Treat the patient instantly on the spot, in the op)cn air, freely 
exposing the face, neck, and chest to the breeze, except in severe weather. 

2d. In order to clear the throat, place the patient gently on the face, 
^vith one wrist under the forehead, that all fluid, and the tongue itself, 
may fall forward, and leave the entrance into the windpipe free. 

3d. To excite respiration, turn the patient slightly on his side, and 
apply some irritating or stimulating agent to the nostrils, as veratrine, 
dilute ammonia, etc. 

4th. Make the face warm by brisk friction ; then dash cold water 
upon it. 

5th. If not successful, lose no time ; but, to imitate resinration, place 
the patient on his face, and turn the body gently, but completely, on the 
side, and a little beyond ; then again on the face, and so on, alternately. 
Repeat these movements deliberately and perseveringly, fifteen times only 
in a minute. (When the patient lies on the thorax, this cavity is com- 
pressed by the weight of the body, and ea;piration takes place. When he 
is turned on the side, this pressure is removed, and mspiration occurs. ) 

6th, Wlien the prone position is resumed, make a uniform and efficient 



APPENDIX. 181 

pressure along the sjnnc, removing the pressure immediately, before rota- 
tion on the side. (The pressure augments the expiration ; the rotation 
commences mspiration. ) Continue these measures. 

7th. Rub the limbs upward, with firm pressure and with energy. 
(The object being to aid the return of venous blood to the heart. ) 

8th. Substitute for the patient's wet clothing, if possible, such other 
covering as can be instantly procured, each bystander supplying a coat or 
cloak, etc. Meantime, and from time to time, to excite inspiration, let 
the surface of the body be slapped briskly with the hand. 

9th. Rub the body briskly till it is dry and warm, then dash cold 
water upon it, and repeat the rubbing. 

Avoid the immediate removal of the patient, as it involves a dangerous 
loss of time — also, the use of bellows, or any forcing instrument ; also, 
the ivarm bath, and all rough treatment. 



The Care of the Siek-room. 

The sick-room should be bright and airy, and "Sweetness and light" 
its motto. Other things being equal, it is best on one of the upper 
floors : — in the case of some "catching "^ disease on the top floor. Let it 
be on the sunny side of the house. If for any reason the light of the sun 
is temporarily to be avoided — as when the eyes are sensitive or have been 
operated upon — let the light be shut out by a proper arrangement of 
blinds or curtains. The air-supply to be breathed by the sick person 
should be pure. Those who, in health, find themselves in an impure air 
can quit it ; they are not compelled to suffer from it ; but a sick person 
may be incapable of recognizing the bad quality of the air, as well as 
helpless to free himself from it. 

To keep the air pure, the windows should be opened as often as three 
times a day, care being taken to protect the patient from being chilled, 
while the room is being aired. 

Unless the physician shall direct differently, one window — that most 
remote from the bed — should be open an inch or more both day and 
night, and in all seasons. The extent to which the sash shall be lowered 
must be governed largely by the weather and the direction of the 
"vvind. 

A fire, in an open fireplace, except in summer weather, will be a great 
help towards keeping the air pure. The upward current through a chim- 
ney flue, if unobstructed, is equal to or not far below 20,000 cubic feet 
per hour : an outlet sufficient for a room occupied by ten persons. 

The inlet of air, hoAvever, must not be forgotten, otherwise the air of the 



182 APPENDIX. 

room tends to become both impure and too thin. As om- bouses are 
generally constructed, the inlet of air is best secured by a Avindow-sasli 
being lowered from the top. 

Take special care that no stationary wash-basin or other sewer- 
connected convenience is improperly plumbed, and that sewer gas cannot 
by any possibility escape into the sick-room. 

The swinging of doors to create a current is not an efficient means 
of ventilation, as it agitates the air of the room without purifying it, and 
often disturbs the patient, 

A draught of au- is to be avoided ; it will seldom occur that the air of 
the room requires to be so speedily changed that the tpatieut need be 
exposed to a draught ; never, when care has been taken to provide con- 
tinuous and gradual ventilation. 

It should be borne in mind that cold air is not necessarily pure air, 
and that ventilation is not less needed in winter than in warm weather. 

Sleep is a great necessity to the sick. If a well person slumbers in the 
day-time, it will interfere with his sound repose at night, but with the 
sick this is generally not the case. The more they sleep the more favor- 
able are the chances for their recovery : so that it will be readily seen 
how important it is to avoid noise and jar in the sick-room, especially if 
the disease is acute. 

Bear in mind that even slight noises, as the rustling of garments, the 
creaking of doors, whispering or noisy footfalls, may be sufficient to 
disturb a brain that is rendered sensitive by pain or wakefulness. 

The clothing next the skin should be changed more frequently in sick- 
ness than in health. These changes must be quickly and deftly 
made, and with as little disturbance as possible. 

Under some conditions of disease, the best welfare of the patient is 
accomplished by having two beds in the room instead of one. 

The temperature of the room must be watched. To that end a ther- 
mometer should always be present, and easily approached. It is better 
not to have it directly in the view of the patient. The temperature 
should not be allowed to vary much from 65° F., unless the doctor other- 
wise directs. 

Let the furniture be as plain and as free from upholstery as possible : 
not many pieces are required. ]\[ovable carjiets or rugs are better than 
those that are permanently laid. Curtains about the windows are out of 
place in a sick-room : so are flowering plants and birds, as a general rale. 
Florence Nightingale, however, makes an exception in the case of chronic 
invalids, and consents to the comfortinor influence of a pet bird or two. 

In regard to the a Imission of visitors and conversation, much will 
depend upon the strength of the patient and the kind of sickness : at 



APPENDIX. 183 

many times these are to be forbidden, as having a disquieting influence. 
AYhen contagious disease is in the house, the sick-room must be avoided 
by all except those who have the care of the patient, and those having 
this care should avoid coming in contact with the other members of the 
household, especially the children. 

Bear in mind that everything brought in contact with the sick is liable 
to endanger the health of the well. 

i!^o articles in use by the invalid should be removed or used by others 
until thoroughly disinfected : the dishes and spoons should be put in 
boiling water before being taken from the room. The room itself should 
be fumigated with sulphur when the person is removed from it. 

Old pieces of muslin, etc. , may be used instead of handkerchiefs to 
receive the poisonous discharges from the nose, mouth, and throat. These 
can be destroyed by fire, and thus prevent the danger of conveying the 
disease to others. 

"Taking the breath" and kissing should be avoided by those in at- 
tendance upon the case. 

The bottles of medicine and other reminders of illness should, as far as 
convenient, be withdrawn from the view of the sick. 

Such as are to be kept always at hand, should be arranged in an orderly 
way upon a tidily-covered bed-side table. The sight of a siphon-bottle of 
aerated water is agreeable to most patients : that may be kept in the 
room, but the vessels containing milk, drinking-water, etc., should be 
kept elsewhere. 

disinfection. 

Filth fosters or produces certain diseases ; it should therefore be re- 
moved as soon as possible. When it is difficult to remove it, disinfectants 
come into play, as they have the power to rob it of some of its disease- 
making force. But let it be remembered that disinfection is not cure : it 
is not a substitute for cleanliness and pure air. The true cure is the re- 
moval of filth : and when our homes are concerned in some question of 
drainage where the filth is out of our sight, it may be necessary to consult 
and employ the plumber or some other artisan. 

In times gone by, it was the custom to mask bad smells by burning 
pastiles, coffee, cascarilla, and the like. These are not now much used, 
for most persons have come to understand that the fumes thus created do 
not remove but simply overpower the evil odors. 

Chemistry has advanced to such a point that various pungent chemical 
substances, formerly not well known, can be furnished at small cost, and 
these substances have the power, in varying degrees, to check vile odorSi 



184 APPENDIX. 

Carbolic acid, chloride of lime, and Labarraque's solution are among the 
best known of these, but there are also certain of the salts of iron and 
zinc and the permanganate of potash that may be used. Sulphuf is much 
used for the fumigation of rooms that have been infected. 

Another cheap disinfectant is a solution of chloride of lead. It is in- 
odorous, effective, and the cost is small. Take half a drachm of the 
nitrate and dissolve it in a pint or more of boiling water. Dissolve two 
drachms of common salt in a pail or bucket of water : pour the two solu- 
tions together and allow the sediment to sink. A cloth dipped in this 
solution and hung up in a room will correct a bad odor promptly, or if the 
solution be thrown down a drain or upon foul-smelling refuse, it will have 
the same effect. 

The room to be purified with sulphur should be made as tight as 
possible, so that no fumes can escape, either by window, door or chimney. 
Put three pounds of sulphur in an iron pot, which should not stand upon 
woodwork or carpet, lest they be burned, but in a large pan of ashes, or 
upon a layer of bricks ; on this sulphur pour a table -spoonful of alcohol. 
This is then set on fire, and everybody immediately withdraws from the 
room. The room should remain closed' ten hours, after which it should 
be thoroughly aired before it is occupied, for the fumes of the sulphur are 
irritating to the lungs. 

The chemicals above mentioned should be known and labeled as 
poisons. Many persons have been injured, if not killed, by incautiously 
or ignorantly drinking those that are of a liquid form. 

Heat is one of the best, if not the best disinfecting agent. Articles of 
bedding and furniture that cannot well be treated otherwise can be purified 
by a long exposure to a temperature of 240" F. In some cities, especially 
in England, furnaces are made for the reception of bulky articles that 
have become infected. 

Fresh pure air is another powerful agent. If woven fabrics, clothiug 
and the like are for a long time aired out of doors, they cease to be 
infective ; probably by the enormous dilution, if not destruction, of the 
elements of danger. 

Certain diseases are "catching" ; they have the power of spreading 
from one person to another, chiefly by the particles that pass off from the 
body of the patient. Among these diseases are small-pox, measles, scarlet 
fever, and diphtheria. The articles that are worn or used by the patient 
become "infected," and they should be disinfected before they are used 
by others. As a rule, of course, a doctor ^vill be called in to attend to 
these diseases. 'WTien that is so, follow his directions as to disinfection 
as well as every other part of the treatment of the case. For substances 
that are not injured by being washed, a good and cheap disinfectant is- 



APPENDIX. 185 

sulphate of zinc ("white vitriol") and common salt dissolved in water, 
boiling-hot if possible : using eight table-spoonfuls of the zinc and four of 
salt to the gallon of water. This is useful for clothing, bed-linen, towels, 
handkerchiefs, etc. After these articles have lain for an hour or two in 
this solution, they should be allowed to stand in boiling water before 
being washed. Infected articles that are of little value should, of course, 
be destroyed by fire. 

The United States Treasury Department has published the following 
formula for the disinfection of the rags coming from Egypt : "1, Boiling 
in water for two hours under a pressure of fifty pounds per square inch ; 
2. Boiling in water for four hours without pressure ; or, 3. Subjection to 
the action of sulphur fumes for six hours, burning one and one-half to two 
pounds of roll brimstone in each 1,000 cubic feet of space, with the rags 
well scattered upon racks. " Either of these three methods is accepted as 
sufficiently thorough to prevent the spreading of cholera by means of 
rags. 

£inerg^eiicie§. 

" 'Tis all in being ready." — Hamlet. 

The life of many a child has been saved by the fire-drill in schools, 
and great good has been done on shipboard by a drilling of the crews. 

If in a building filled with smoke, get down on hands and knees and 
crawl to door or window. 

In a cellar, well, or vat where carbonic acid can collect, the true posture 
is to stand erect. If a candle, on being lowered into a suspected place, is 
put out, you may know that there is danger to human life. 

Bums and Scalds. — The secret_of the best treatment of these in- 
juries is to exclude the air from the wounded surfaces. When they are slight, 
and the skin is not destroyed but merely blistered, prevent the displacement 
of the skin as much as possible. Let the blisters be punctured, if neces- 
sary, to let out the liquid, and then keep the skin in place by cotton cloth 
or lint, wet with a solution of one teaspoonful of carbolic acid in a quart 
of water, or a strong solution of baking soda. The cloth should -be kept 
wet constantly, but do not irritate the wound by taking off the dressing 
too often. 

Extensive burns are much worse than deep burns. In the former case, 
the outlook is grave and the patient will probably require the best aid, 
both medical and surgical, of some ])hysician. 

ISc^ars after Burns.— If a burn be on the face, neck, or near a 



186 APPENDi::. 

joint, it U not well to hasten the healing process, on account of the con- 
traction that always takes place as the scar is formed. 

** Fire is a source of danger, and is very destructive to life at times. 
Spontaneous combustion of the human body when saturated with alcohol 
is a myth, though perhaps the alcoholized body does burn more readily 
than one free from inflammable fluid. When a lady is on fire, she should 
not, and ought not to be permitted to run ; that fans the flames amazingly. 
She must be laid down, and rolled up in the nearest woollen article, — rug, 
coat, or blanket. Such wrapping up in a non-inflammable article is a 
most eff'ective method of extinguishing the flames. Immersion in water 
is, unfortunately, rarely practicable. " — Fothergill. 

Illtliniliatillg Oas is dangerous in two ways. If it escapes into a 
tightly closed room in sufficient quantities, it causes the death of the in- 
mates by suff"ocation, unless some one from without discovers the j)erilous 
situation. If not too late, remove the patient into fresh air, undo the 
clothing, dash cold water on the face and neck, and employ artificial res- 
piration, as in drowning (see p. 180). Again : If it escapes freely into an 
apartment, it forms an explosive compound b}' mixipg with the air. If 
then a light is unguardedly taken into the place, an explosion that may 
be destructive to life will result. Always thoroughly air any room that 
has the odor of escaping gas before a light is taken in. 

Kerosene is the cause of even more " accidents " than gas. Too much 
care cannot be taken in its use. Buy only that which has been tested, 
but remember that not all that are marked as "safe" are truly so. If a 
responsible oil-man certifies that the oil will not "flash" under 140°, it 
may be regarded as safe if properly used. Lamps should only be filled in 
the daytime. Never attempt to fill a lamp that is lighted, and never put 
kerosene in the stove for the purpose of kindling a fire. Very small lamps 
are dangerous, as also is a lamp that has burned a long time, and has but 
very little oil in it. 

Frost-bites. — Keep away from the fire and in a cool room. Rub the 
nose or other part that has been " bitten " with snow or ice-water until 
the blood again is w^armed and circulating in the part. Chilblains should 
not be brought to the fire ; if the skin is unbroken, it should be hardened 
by brushing it over Avith alcohol having tannin in it. 

Cuts. — These, if severe, should be promptly attended by a physician, 
but every one should know^ how^ to treat small w^ounds. Learn the differ- 
ence between the two kinds of bleeding, called " arterial" and "venous." 
Arterial is bright red and comes in jets (or with throbs corresponding to 
the pulse) ; venous is dark colored and flows continuously. In the former, 
press on that side of the wound nearer to the heart ; in the latter, on the 
further side. Or, pressure may be made over the wound itself with the 



APPENDIX. 187 

fingers : this may stop tlie loss of blood from small arteries as well as 
from veins. Loss of blood from arteries is apt to be more rapid and dan- 
gerous than that from veins, and when the cut vessel is a large one, the 
skill of the surgeon Avill ordinarily be required in order to close the 
bleeding artery permanently and securely. 

It is well, in every household, to have, in some handy and well-known 
place, some strips of old muslin and some lint, or oakum, a bandage or 
two and some adhesive plaster, a soft sponge, and needles and thread in a 
basket or box by themselves. In this way, valuable time may be saved 
in the staunching of blood, flowing in consequence of some accidental cut 
or other injury. 

Fits or Convulsions. — These may be trivial or grave. If it is a 
young woman, the attack is probably hysterical and, as a rule, not dan- 
gerous, and a sprinkle of cold water will bring relief. If the patient strug- 
gles with regularity of movement, and there is bloody froth on the lips, it 
is a case of epilepsy, and requires a physician's attendance. Meanwhile, 
protect the head from injury by putting a pillow or some soft article beneath 
it ; a cork introduced between the teeth wdll prevent the biting of the 
tongue. Prevent the person from falling or injuring himself, but do 
not attempt to forcibly hold him quiet. 

In children, apply cloths dipped in water to the head ; disturb the 
child as little as possible ; do not use a warm bath until directed by the 
doctor. 

Fainting. — This occurs when the blood is deficient in the brain. The 
proper jiosition, therefore, is upon the back. Let the window be opened 
to admit fresh air ; fanning, and the sprinkling of water are useful. If the 
clothing about the chest is tight, let it be loosened. If the faint occurs 
at church or some public gathering, remove the person promptly to the 
outer air : for foal air is frequently the cause of the trouble. 

Vertigo. — This is "a rush of blood to the brain." The body should 
be placed in the sitting posture, with the head erect. If the blood escapes 
into the brain by reason of the rupture of a blood-vessel within it, the 
case is very grave, and the physician should be summoned at once. 
Meanwhile, let the position of the body be as above stated. Apoplexy is 
known, in very many cases, by the helpless condition of an arm or leg, or 
both. 

Sunstroke is seldom produced in this climate in persons who have 
not labored too hard. Fatigue and sun-heat are commonly the joint causes 
of sudden prostration in summer ; although " heat-stroke " may occur in 
an artificially-heated atmosphere, without exposure to the sun. In the 
tropics, the least possible exertion is by the natives ])ut forth during the 
midday hours. On very hot days, therefore, avoid fatigue and labor in 



188 APPENDIX. 

tlie open air as much as possible. Keep the head cool. If any unusual, 
dizzy feeling comes on, apply cold water to the head and neck. If a 
person falls unconscious and the skin is decidedly hot and dry, he should 
be taken to a cool place. If the face and head are red and hot, apply ice- 
water on cloths. If pale, give stimulants gradually and use cold water 
sparingly. 

Shock may be caused by a fall or a blow upon the head or the pit of the 
stomach. It is kno^vn by slowing of the pulse and respiration ; the face 
is pale and the skin becomes cool. The head should be placed low, some 
ammonia in water be given and warmth applied to the surface of the 
body. 

The Home and Health. 

The location of the house should be airy, dry, and sunny. 

A certain amount of elevation is necessary, in order to secure proper 
drainage. Too much shade must not fall upon the house, as sunlight is 
very necessary to a proper degree of animal vigor. Young children, as is 
well known, especially profit by the tonic influence of sunlight. 

The cellar is an important part of the dwelling ; therefore, unless care 
be taken for its ample ventilation, it will be the source from which is sup- 
plied much of the air breathed in the upper chambers of the house. If 
the cellar is damp the house is liable to become so, and if vegetables are 
stored in the cellar, an especial degree of care is needed to ventilate it 
thoroughly and constantly. 

House Drainage. — An English ^mter has stated that "the most 
important part of the house is the drains." This, no doubt, sounds 
strangely to the ears of many, who have been brought up to view the 
parlor or drawing-room as the true centre of the house, and yet it is no 
foolish saying, when we reflect that with a bad system of drainage to a 
house every dweller therein stands in peril of several forms of disease that, 
mild as the cases may be, are a source of anxiet}^ and Avhen severe, too often 
have a fatal termination. Drain-diseases, such as typhoid fever, dysentery, 
diphtheria, and scarlet fever, often destroy entire families. These diseases 
do not always spring upon a home through defective drainage, but when 
they do, they frequently shoAv themselves in a very violent form. 

Drainage (as applied to dwellings) consists in conveying away from the 
house the liquid and solid impurities that would otherwise accumulate in 
or near the dwelling. Waste is a necessary accompaniment of all animal 
life, to the preparation and the taking of food, to the clothing of the body,, 
to bathing and other simple acts of daily life. The waste material of 
houses tends to decay and to become oflensive. It must, therefore, not 



APPENDIX. 189 

only be put out of sight and smell, but must be removed so far away that 
it cannot return in the form of dangerous, invisible gases of decomposi- 
tion. 

The best house-drains are made of iron or glazed earthenware,, carefully 
selected and well laid. The joints of the pipes should be gas-tight. The 
soil-pipe should be carried up to and through the roof. All the waste- 
pipes from basins, etc., in the rooms should be joined in a gas-tight 
manner to the soil-pipe, and each and every basin and other fixture 
should have a separate trap. "What is a trap ? It is a device that is 
designed to retain a certain portion of the water running through it — 
called the " water-seal " — so that the ascent of air or gas, from the drain 
back into the room, is prevented. It " traps " the sewer gas away from 
us. Whenever a fixture has been used and there is not, beyond all doubt, 
a sufficiency of water to fill the trap, additional water should be poured 
in. Traps are of various sizes, and of an infinite variety of patterns and 
patents, and must vary greatly according to their situation, but one thing 
should be made sure of in their use, namely, that they hold not less than 
two inches of water as a "seal." 

There is at almost all seasons of the year an upward, because warmer, 
current of air through the main pipes. It is therefore better to have a 
fresh-air inlet pipe near the point where the drain leaves the house-wall. 
This helps to prevent the unsealing of traps. It also brings about a purer 
condition of the air in the interior of the system of pipes : so useful is 
this air-current through the soil-pipe that if applied there is little danger 
of the escape of sewer gas into the living rooms. 

What is sewer gas or sewer air ? It varies greatly in different places 
and at different times. It is not a definite gas, like oxygen, nitrogen, 
etc. , but varies in composition, and what is still more Avorthy of note, it 
varies in its dangerous qualities. It is not always offensive, although it 
is generally so ; its odor has been described as being ' ' sweetish and 
sickish." Its dangerous qualities have not yet been determined by chem- 
istry or the microscope, but one practical point may be borne in mind, 
namely, that when a case or cases of contagious disease occur in any 
house along any given line of sewer pipes, it is best to use disinfectants in 
the drainage of the other dwellings along the same line of sewer. Chil- 
dren should avoid playing over or around the sewer gratings in the 
streets at all times, and especially when scarlet fever and like conta- 
gious diseases are known to be in the neighborhood, for the exit of 
sewer air at these points is always very free, unless it be directly after a 
i-ainfall. 

One other point must be remembered, that the best laid system of 
house plumbing is not indestructible. In the course of time, defects wiU 



190 APPENDIX.. 

arise, breaks will occur ; for this reason it would be well for every house- 
holder to have an examination made at intervals of every joint and along 
the whole line of the house connection with the sewer or drain. 

It is thought by many that sewer gas is not found in the country 
because there are no sewers : they have been misled by the word. If the 
words "drain air'' or " filth gas " had been adopted, the universal pro- 
duction of this injurious substance, in close connection with every abode 
of man, Avherever located, might have been better understood. In country 
houses there are, perhaps, fewer dangers of contamination of the air we 
breathe by waste products, because there are fewer water-closets, wash- 
basins, sinks, etc., and the rooms are less exposed to impure air. 

But in the country danger is apt to come by or through the pollution 
of the water supply. The well, which furnishes that cool and refreshing 
draught, is the point to be watched. It is convenient to have the well 
near the house, because when snow is on the ground and the weather is 
cold, the distance to the well from the house is a matter of no small 
moment. Xear the house must be the stable and pens for animals : the 
waste from the house goes upon the ground, and not very far away from 
the house : the chamber slops and the more offensive matters go into a pit, 
which must not be too distant. The result of all these conditions is a 
pollution of the soil at all these points — a pollution which spreads with 
every rainfall, and which, sooner or later, reaches the well ; yet the water 
may appear as pure as ever. It only remains to have the suitable disease- 
germ lodged in this polluted territory to bring down the whole household 
Mith a fever. This is the kind of soil-pollution which is hard to ciire, and 
which, in long-settled countries, causes laws to be enacted requiring all 
vaults for the reception of house and human waste to be made water- 
tight, so as to save the soil from its poisoning influence. 

This is the kind of poisoning which, in the Dark Ages, caused so much 
unrighteous persecution of the innocent. In those days, no care whatever 
was taken in the towns, high-walled, crowded, and uusewered, to protect 
the water supply from pollution : as a result, some terrible epidemic of 
fever would arise. Then the angry populace would, in theii' ignorance, 
cry out : " The Jews have poisoned the wells." The wells were poisoned, 
no doubt, but the Jew was no more worthy of blame than were his 
accusers. Nevertheless, the Jews were not spared : they were robbed, 
imprisoned, executed. 

Drainage in the city is a comparatively easy problem when the city's 
sewers are laid in the streets. In the country it is more difficult, and on 
this account the fewer fixtures or "modern improvements" there are in 
the house the better it will be. There should be no less care A\dthin the 
country house, where waste-pipes are put in, than in the city house. 



APPENDIX. 191 

Tlie material should lie well selected, tightly joined, and properly ven- 
tilated. The water-closet should be remote from the house. Earth- 
closets are better than the ordinary vaults — house-Avaste from kitchen and 
laundry should be taken to a considerable distance from the house, and 
far away from the well, and either deposited in a water-tight cesspool or 
conveyed away, by a system of subsoil drainage tiles, arranged so as to 
fertilize some unoccupied plot of ground. 



On Going into the Country. 

To spend the summer in the country would be the choice of all city- 
dwellers, whenever their purses Avill permit of it. And there are not a few 
advantages in such a course ; the change of scene is good, the mountains 
and the seaside give a purer and cooler air : an air that invigorates and 
aids in restful sleep at night, so different from the midsummer atmosphere 
in hot cities. There are fewer excitements in the country ; we do not 
*• live so fast," and there is full scope for healthful life and activity in the 
open air, with the green and blue of nature all about us, instead of the 
monotonous walls of towering houses. 

But this course, pleasant and helpful to so many, is not without its 
danger. Many who " go away " on vacation are brought home sick on 
account of fever or other sickness caused by defects and faults of drainage 
existing in these temporary summer homes. Scarcely a year goes by that 
one or more summer resorts have not gained the ill name of being the 
hotbeds of typhoid fever, dysentery, and the like. 

In view of this, how important it becomes that we exercise judgment 
and seek skilled advice in the selection of our summering places. 

Again, there is another danger that must not be overlooked. Let us 
suppose that the summer vacation has passed by without accident ; that 
we return invigorated by the experience ; and that the home in the city 
has been empty and closed during our absence ; what has happened that 
the air in the rooms newly reopened should be foul and stifling ? This 
has taken place ; the water that stands in the traps of house pipes, and 
shuts off gases from the sewer, when the rooms are in use and Avater is daily 
entering the different Avash-basins, etc., has during our absence been 
evaporated. For weeks, perhaps, there has been no " Avater-seal " in the 
traps, and the ascent of scAver air has been going on continuously, so that 
not only is the air utterly unfit to live in, but all the curtains, carpets, 
and other absorbing materials have become saturated Avith the pollu- 
tion thus alloAved to enter. Let it be remembered that AAdien a sink, etc. , 
is not in use, it is gradually losing the trap-Avater by the evaporation. 



192 APPENDIX. 

What is the remedy, you will ask, for the condition of things caused by 
closing up the house, as above stated ? To this the reply is, that the 
house should from time to time be opened and aired, and water should be 
poured down each and every sanitary fixture, in sufficient quantity to 
renew the supply of water in the trap of each. 



GLOSSARY. 



Ab-do'men (Latin abdo, to conceal). The largest cavity of the body, con- 
taining the liver, stomach, intestines, etc. ; the belly. 

Ab-sor'bents (L. ab and sorbeo, to suck up). The vessels which take 
part in the process of absorption. 

Ab-sorp'tion. The process of sucking up fluids by means of an animal 
membrane. 

Ac-com-mo-da'tion of the Eye. The alteration in the shape of the crys- 
talline lens, which accommodates or adjusts the eye for near and remote 
vision 

Ac'iD, Lactic (L. lac, milk). The acid ingredient of sour milk ; the 
gastric juice also contains it. 

Al-bu'men, or Albumin (L. albus, white). An animal substance resem- 
bling white of egg. 

Al-bu'mi-nose (from albumen). A soluble animal substance produced in 
the stomach by the digestion of the albuminoid substances. 

Al-bu'min-oid substances. A class of proximate principles resembling 
albumen ; they may bd derived from either the animal or vegetable 
kingdoms. 

Al'i-ment (L. alo, to nourish). That which affords nourishment ; food. 

Al-i-ment'a-ry Ca-nal (from aliment). A long tube in which the food 
is digested, or prepared for reception into the system. 

An-^s-thet'ics (Greek, av, an, without, ah'&ijata, aisthesia, feeling). 
Those medicinal agents which prevent the feeling of pain, such as 
chloroform, laughing-gas, etc. 

An-i-MAl'cule (L. animal' culum, a small animal). Applied to animals 
which can only be seen with the aid of the microscope. Animalculum 
(plural, animalcula) is used with the same meaning. 

A-or'ta (Gr. dopTEOjuai, aorteomai, to be lifted up). The largest artery of 
the body, and main trunk of all the arteries. It arises from the left 
ventricle of the heart. The name was first applied to the two large 
branches of the trachea, which appear to be lifted up by the heart. 

A'que-ous Humor (L. aqua, water). A few drops of watery colorless 
fluid occupying the space between the cornea and crystalline lens. 



194 GLOSSARY. 

A-each'noid Mem'braxe (Gr. dpuxvv, arachnc, a cobweb, and eISo^, 

eidos, like). An extremely thin covering of the brain and spinal cord. 

It lies between the dura mater and the pia mater. 
Ar'bor Yi't^ (L.). Literally, "the tree of life ;" a name given to the 

peculiar appearance presented by a section of the cerebellum, 
Ar'tery (Gr. d?jp, aer, air, and TTJpeiv, terein, to contain). A vessel by 

which blood is conveyed away from the heart. It was supposed by the 

ancients to contain air ; hence the name. 
Ae-tic-i:-la'tion (L. articulo, to form a joint). The more or less mov- 
able union of bones, etc. ; a joint. 
A-ryt'e-xoid Car'ti-la-ges (Gr. upvraLva, arutaina, a pitcher). Two 

small cartilages of the larynx, resembling the mouth of a pitcher. 
As-sim-i-la'tiox (L. ad, to, and siniilis, Hke). The conversion of food 

into living tissue. 
Atj-di'tion (L. audio, to hear). The act of hearing sounds. 
Au'di-to-ry Xerve. One of the cranial nerves ; it is the special 

nerve of hearing. 
Au'ri-cle (L. auris, the ear). A cavity of the heart. 
Bar'i-tone (Gr. ^apvg, harus, heavy, and rovog, tonos, tone). A variety 

of male voice between the bass and tenor. 
Bel-la-dox'xa (It. beautiful lady). A vegetable narcotic poison. It 

has the property of enlarging the pupil, and thus increasing the 

brilliancy of the eye ; so called from its use by Italian ladies. 
Bi-crs'piD (L. hi, two, and cuspis, prominence). The name of the fourth 

and fifth teeth on each side of the jaw ; possessing two prominences. 
Bile. The gall, or peculiar secretion of the liver ; a viscid, yellowish 

fluid, and very bitter to the taste. 
Broxch'i (Gr. ^poyxoc, bronkos, the windpipe). The two first divisions 

or branches of the trachea ; one enters each lung. 
Bronch'i-al Tubes. The smaller branches of the trachea Avithin the 

substance of the lungs, terminating in the air-cells. 
Bronch-i'tis (from bronchia, and itis, a suffix signifying inflammation). 

An inflammation of the larger bronchial tubes ; a "cold" affecting the 

lungs. 
Cal-ca're-ous (L. calx, lime). Containing lime. 
Ca-nal' (L. ). In the body, any tube or passage. 
Ca-nine' (L. canis, a dog). Kame given to the third tooth on each side 

of the jaAv ; in the upper jaw it is also known as the eye-tooth, pointed 

like the tusks of a dog. 
Cap'il-la-ry (. capiVlus, a hair, capiUa'ris, hair-like). The name of the 

extremely minute blood-vessels which connect the arteries with the 

veins. 



GLOSSAEY. 195 

Car'bon Drox-iDE (COo). Chemical name for carbonic acid gas. 
Car-bon'ic A'cid. The gas which is present in the air expired from the 

lungs ; a waste product of the animal kingdom, and a food of the 

vegetable kingdom. 
Car'di-ac (Gr. Kapdia, cardia, the heart). The cardiac orifice of the 

stomach is the upper one, and is near the heart ; hence its name, 
Car-niy'o-rous (L. ca'iv, flesh, and vo'ro, to devour). Subsisting upon 

flesh. 
Ca-rot'id Ar-te-ry. The large artery of the neck, supplying the head 

and brain. 
Car'ti-lage. a solid but flexible material, forming a part of the joints, 

air-passages, nostrils, ear ; gristle. 
Ca'se-ine (L. ca'seus, cheese). The albuminoid substance of milk, it 

forms the basis of cheese. 
Cer-e-bel'lum (diminutive for cer'ehruTn, the brain). The little brain, 

situated beneath the posterior third of the cerebrum. 
Cer'e-brum (L. ) The brain proper, occupying the entire upper portion 

of the skull. It is nearly divided into two equal parts, called ' ' hemi- 
spheres," by a cleft extending from before backward. 
Cho'roid (Gr. x^piov, chorion, a membrane or covering). The middle 

tunic or coat of the eyeball. 
Chyle (Gr. ;t'^/l6f, chidos, juice). The milk-like fluid formed by the 

digestion of fatty articles of food in the intestines. 
Chi^me (Gr. A^v,u6f, chumos, juice). The pulpy liquid formed by digestion 

within the stomach. 
Cil'i-a (pi. of ciV i-uiii, an eyelash). Minute, vibratile, hair-like pro- 
cesses found upon the cells of the air-passages, and other parts that are 

habitually moist. 
Cir-cu-la'tion (L. cir' cuius, a ring). The circuit, or course of the blood 

through the blood-vessels of the body, from the heart to the arteries, 

through the capillaries into the veins, and from the veins back to the 

heart. 
Co-AG-r-LA'TiON (L. cottg'ulo, to curdle). Applied to the process by 

which the blood clots or solidifies. 
Coch'le-A (L. coch'lea, a snail-shell). The spiral cavity of the internal 

ear. 
Conch'a (Gr, Kovxv, koiiche, a mussel-shell). The external shell-shaped 

portion of the external ear. 
CoN-JUNC-Ti'vA (L. con and jun'go, to join together). A thin layer of 

mucous membrane which lines the eyelids and covers the front of the 

eyeball ; thus joining the latter to the lids. 



196 GLOSSARY. 

Cox-trac-til'i-tt {L. con and tra'ho, to draw together). The property 
of a muscle which enables it to contract, or draw its extremities closer 
together. 

Con-vo-lu'tions (L. con and vol'vo, to roll together). The tortuous fold- 
ings of the external surface of the brain. 

Con-vul'sion (L. conveVlo, to puU together). A more or less violent 
agitation of the limbs or body. 

Cor'ne-a (L. cor'nu, a horn). The transparent, horn-like substance 
Avhich covers the anterior fifth of the eyeball. 

Cor'pus-cles, Blood (L. dim. of cor'^ms, a body). The small bi-concave 
disks which give to the blood its red color ; the tchite corpuscles are 
globular and larger. 

Cos-met'ic (Gr. Koofieu, Jcosmeo, to adorn). Beautifpng ; applied to 
articles which are supposed to increase the beauty of the skin, etc. 

Cra'ni-al (L. cra'niiim, the skull). Pertaining to the skull. The nerves 
which arise from the brain are called cranial nerves. 

Cri'coid (Gr. /cpZ/cof, Tcri'Tcos, a ring). A cartilage of the larynx resem- 
bling a seal-ring in shape. 

Crts'tal-line Lens (L. crystaVlum, a crystal). One of the so-called 
humors of the eye ; a double convex body situated in the front part of 
the eyeball. 

Cu'ti-cle (L. dim. of cu'tis, the skin). The scarf-skin ; also called the 
epider'mis. 

Cu'tis (Gr. cKvrog, shutos, a skin or hide). The true skin, lying beneath 
the cuticle ; also called the der'mis. 

De-cus-sa'tiox (L. decus'sis, the Roman numeral ten, X). A reciprocal 
crossing of fibres from side to side. 

Di'a-phragm (Gr. 6ta(j)puaao), dmphrasso, to divide by a partition). A 
large, thin muscle which separates the cavity of the chest from the 
abdomen ; a muscle of resjnration. 

DiF-FUs'iON OF Gases. The power of gases to become intimately 
mingled, -v^-ithout reference to the force of gravity. 

Duct (L. dit'co, to lead). A narrow tube ; the thoracic duct is the main 
trunk of the absorbent vessels. 

Du-o-de'num (L. duode'ni, twelve each). The first di^dsion of the small 
intestines, about twelve fingers-breadth long. 

Du'ra Ma'ter (L.). Literally, the hard mother; the tough membrane 
which envelops the brain. 

Dys-pep'si-a (Gr. Svg, dus, difficult, and TreTrrw, 2)epto, to digest). Diffi- 
cult or painful digestion ; a disordered condition of the stomach. 

E-mul'sion (L. emul'e/60, to milk). OH in a finely di^dded state sus- 
pended in water. 



GLOSSARY. 197 

En-am'el (Fr. email). The dense material which covers the crown of the 

tooth. 
En'er-gy, Specific, of a Nerve, AVlien a nerve of special sense is excited, 

whatever be the cause, the sensation experienced is that peculiar to the 

nerve ; this is said to be the law of the specific energy of the nerves. 
Ep-i-glot'tis (Gr. ettl, epi, upon, and yldtTig, glottis, the entrance to the 

windpipe). A leaf-shaped piece of cartilage which covers the top of the 

larynx during the act of swallowing. 
Ex-cre'tiox (L. excer'no, to separate). The separation from the blood of 

the waste particles of the body ; also the materials excreted. 
Ex-pi-ra'tiox (L. expi'ro, to breathe out). The act of forcing air out of 

the lungs. 
Ex-ten'sion (L. ex, out, and ten' do, to stretch). The act of restoring a 

limb, etc. , to its natural position after it has been flexed, or bent ; the 

opposite of Flexion. 
Fe-nes'tra (L. ). Literally, a window ; the opening between the middle 

and internal ear. 
Fi'brin (L. fi'hra, a fibre). An albuminoid substance found in the blood ; 

in coagulating it assumes a fibrous form. 
Flex'ion (L. fledo, to bend). The act of bending a limb, etc. 
Fol'li-cle (L. dim. oi fol'lis, a bag). A little pouch or depression in a 

membrane ; it has generally a secretory function. 
Fun'gous Growths (L. fun'gus, a mushroom). A low grade of vegetable 

life. 
Gan'gli-ON (Gr. ydvyliov, ganglion, a knot). A knot-like swelling in the 

course of a nerve ; a smaller nerve-centre. 
Gas'tric (Gr. yaarijp, gaster, stomach). Pertaining to the stomach. 
Gland (L. glans, an acorn). An organ consisting of follicles' and ducts, 

with numerous blood-vessels interwoven ; it separates some particular 

fluid from the blood. 
Glos'so-phar-yn-ge'al Nerve (Gr. yluaaa, glossa, the tongue, and 

(pdpvy^, phariigx, the throat). The nerve of taste supplying the posterior 

third of the tongue ; it also supplies the throat. 
Glu'ten(L.). Literally, glue; the glutinous albuminoid ingredient of 

wheat. 
Gran'ule (L. dim. of gra'num). A little grain ; a microscopic object. 
Gus-ta'tion (L. gusto, to taste). The sense of taste. 
Gus'ta-to-ry Nerve. The nerve of taste supplying the front part of the 

tongue, a branch of the "fifth" i)air. 
Hem'or-rhage (Gr. uifm, hai'ma, blood, and ^fjyvv/ut, rcgmimi, to burst). 

Bleeding, or the loss of blood. 



198 GLOSSARY. 

Hem-i-ple'gia (Gr. rjiiiav^, hemisiis, half, and nXrjaao, 2>lesso, to strike). 
Paralysis, or loss of power, affecting one side of the body. 

Hem'i-SPHEEES (Gr. a<palpa, sjphaira, a sphere). Half a sphere, the lateral 
halves of the cerebrum, or brain proper. 

He-pat' ic (Gr. rj-aap, hepar, the liver). Pertaining to the liver. 

Her-biv'o-rous (L. her' ha, an herb, and vo'ro to devour). Applied to 
animals that subsist upon vegetable food. 

Hu'moPi, (L. ). Moisture : the humors are transparent contents of the eye- 
ball. 

Hy-dro-pho'bi-a (Gr. v6op, hudor, water, and (poBiu, jjhohco, to fear). A 
disease caused by the bite of a rabid dog or other animal. In a person 
affected with it, convulsions are occasioned by the sight of a glittering 
object, like water, by the sound of running water, and by almost any 
external impression. 

Hy'gi-ene (Gr- vyteia, , huygieia, health). The art of preserving health 
and preventing disease. 

Hy'per-o'pi-a. Abbreviated from Hy'pePc-met-eo'pi-a (Gr. vnip, huper, 
beyond, fiirpov, metron, the measure, and uijj, ops, the eye). A defect 
of vision dependent upon a too short eyeball ; so called because the rays 
of light are brought to a focus at a point behind the retina ; the] true 
"far sight." 

In-ci'sor (L. inci'do, to cut). Applied to the four front teeth of both 
jaws, which have sharp cutting edges. 

In'cus (L. ). An anvil J the name of one of the bones of the middle 
ear. 

In-sal-i-ya'tion (L. in, and sali'va, the fluid of the mouth). The min- 
gling of the saliva witla. the food during the act of chewing. 

In-spi-Ra'tion (L. in, and spih'o, sjnra'tum, to breathe). The act of 
draAving in the breath. 

In-teg'u-ment (L. in, and tc'go, to cover). The skin, or outer covering 
of the body. 

In-tes'tine (L. in'tus, within). The part of the alimentary canal which 
is continuous with the lower end of tlie stomach ; also called the intes- 
tines, or the bowels. 

Fris (L. i'ris, the rainbow). The thin muscular ring which lies between 
the cornea and crystalline lens, and which gives the eye its broAvn, blue, 
or other color. 

Ju'gu-lar (L. ju'gulum, the throat). The name of the large veins which 
run along the front of the neck. 

Lab'y-rinth (Gr. XafSvpivdog, laburin'thos, a building with many wind- 
ing passages). The very tortuous cavity of the inner ear, comprsing 
the vestibule, semicircular canals, and the cochlea. 



GLOSSARY. 199 

Lach'ry-mal Apparatus (L. lach'ryma, a tear). The organs for forming 

and conveying away the tears. 
Lac'te-ALS (L. lac, lac' t is, milk). The absorbent vessels of the small 

intestines ; during digestion they are filled with chyle, which has a 

milky appearance. 
La-ryn'go-scope (Gr. "kdpvy^, larugx, the larynx, and aaoTTeu, skopco, to 

look at). The instrument by which the larynx may be examined in 

the living subject. 
Lar'jnx (Gr.). The cartilaginous tube situated at the top of the wind- 
pipe, or trachea; the organ of the voice. 
Lens (L. ). Literally, a lentil ; a piece of transparent glass or other sub- 
stance so shaped as either to converge or disperse the rays of light. 
Lig'a-ment (L. li'go, to bind). A strong, fibrous material binding bones 

or other solid parts together ; it is especially necessary to give strength 

to joints. 
Lig'a-tuee. a thread of silk or other material used in tying around an 

artery. 
Lymph (L. li/m'jjJia, spring-water). The colorless, watery fluid conveyed 

by the lymphatic vessels. 
Lym-phat'ic Vessels. A system of absorbent vessels. 
Mal'le-us (L. ). Literally, the mallet ; one of the small bones of the 

middle ear. 
Mar' ROW. The soft, fatty substance contained in the central cavities of 

the bones : the spinal marrow, however, is composed of nervous tissue, 
Mas-ti-ca'tion (L. mas'tico, to chew). The act of cutting and grinding 

the food to pieces by means of the teeth. 
Me-dul'la Ob-lon-ga'ta. The "oblong marrow," or nervous cord, 

which is continuous with the spinal cord within the skull. 
Mem-bra' NA Tym'pan-i (L. ). Literally, the membrane of the drum ; a 

delicate partition separating the outer from the middle ear ; it is 

sometimes incorrectly called the drum of the ear. 
Mem'brane. a thin layer of tissue serving to cover some part of the bod}^ 
Mi'cro-scope (Gr. fiLKpo^, Tnikros, small, and aaoTrecj, slcopeo, to look 

at). An optical instrument which assists in the examination of minute 

objects. 
Mo'lar (L. mo' la, a mill). The name applied to the three back teeth of 

each side of the jaw ; the grinders, or mill-like teeth. 
Mo'tor (L. mo'vco, ino'tum, to move). Causing motion ; the name of 

those nerves which conduct to the muscles the stimulus which causes 

them to contract. 
Mu'cous Membrane. The thin layer of tissue which covers those internal 

cavities or passages which communicate with the external air. 



200 GLOSSARY. 

Mu'cus. The glairy fluid which is secreted by mucous membranes, and 
which serves to keep them in a moist condition. 

My-o'pi-a (Gr. iiv(j, muo, to contract, and u^, ojjs, the eye). A defect of 
vision dependent upon an eyeball that is too long, rendering distant 
objects indistinct ; near sight. 

Na'sal (L. na'sus, the nose). Pertaining to the nose ; the nasal cavities 
contain the distribution of the special nerve of smell. 

Nerve (Gr. vevpov, neuron, a cord or string). A glistening, white cord 
of cylindrical shape, connecting the brain or spinal cord M-ith some 
other organ of the body. 

Nerve Cell. A minute, round and ashen-gray cell found in the brain 
and other nervous centres. 

Nerve Fi'bre. An exceedingly slender thread of nervous tissue found 
in the various nervous organs, but especially in the nerves ; it is of a 
white color. 

Nu-tri'tion (L. nu'trio, to nourish). The processes by which the nourish- 
ment of the body is accomplished. 

(E-soph'a-gus (Gr. ). Literally, that which carries food. The tube lead- 
ing from the throat to the stomach ; the gullet. 

0-le-ag'i-nous (L. o^leum, oil). Of the nature of oil : applied to an im- 
portant group of food-principles — the fats. 

Ol-fac'to-ry (L. olfa'cio, to smell). Pertaining to the sense of smell. 

Oph-thal'mo-scope (Gr. b(pdalfi6c, opTithahnos, the eye, and otcoTreio, 
sJcopeo, to look at). An instrument devised for examining the interior 
of the globe of the eye. 

Op'tic (Gr. otttu, opto, to see). Pertaining to the sense of sight. 

Or'bit (L. or' Ms, the socket). The bony socket or cavity in which the 
eyeball is situated. 

Os'mose (Gr. cjcjfioc, osmos, a thrusting or impulsion). The process by 
which liquids are impelled through a moist membrane. 

Os'se-ous (L. OS, a bone). Consisting of, or resembling bone. 

Pal' ate (L. ^;aZa7wm, the palate). The roof of the mouth, consisting 
of the hard and soft palate. 

Pal' MAR. Relating to the palm of the hand. 

Pan'cre-AS (Gr. irug, navroc, pcis, pantos, all, and /cpmf, kreas, flesh). A 
long, flat gland situated near the stomach ; in the lower animals the 
analogous organ is called the SAveet-bread. 

Pa-pil'lje (L. pi. of papiVla), The minute prominences in which ter- 
minate the ultimate fibres of the nerves of touch and taste. 

Pa-RAl'y-sis. a disease of the nervous system marked by the loss of 
sensation, or voluntary motion, or both ; palsy. 

Par-a-ple'gi-a (Gr. irapaixT^i^aao), paraplesso, to strike amiss^. A form 
of paralysis affecting the lower half of the body. 



GLOSSARY. 201 

Pa-tel'la (L. dim. oi pat'ina, a pan). The knee-pan ; a small bone. 
Pel'vis (L. ). Literally a basin ; the bony cavity at the lower part of the 

trunk. 
Pep'sin (Gr. TTt-Trrw, ^j<3/;/!o, to digest). The organic principle of the gas- 
tric juice. 
Pericardium (Gr. Tzepl, peri, about, and KupSia, kardia, heart ; the sac 

enclosing the heart. 
Per-i-stal'tic Move'ments (Gr. 7repiaTe?^?iU, peristello, to contract). 

The slow, wave-like movements of the stomach and intestines. 
Per-i-to-ne'um (Gr. TrepiTEivu, periieino, to stretch around). The 

investing membrane of the stomach, intestines, and other abdominal 

organs. 
Per-spi-ra'tion (L. 2Jers2n^ro, to breathe through). The sweat, or watery 

exhalation of the skin ; when visible, it is called sensible perspiration, 

when invisible, it is called insensible perspiration. 
Pe'trous (Gr. -nirpa, petra, a rock). The name of the hard portion 

of the temporal bone, in which is situated the drum of the ear 

and labyrinth. 
Phar'ynx (Gr. (^dpw^^phariinx, the throat). The cavity between the 

back of the mouth and gullet. 
Phys-i-ol'o-gy (Gr. ^vaic^phusis, nature, and "koyo^, logos, a discourse). 

The science of the functions of living, organized beings. 
Pi'a Ma'ter (L. ). Literally, the tender mother ; the innermost of the 

three coverings of the brain. It is thin and delicate ; hence the 

name. 
Pleu'ra (Gr. nXevpu, a rib). A membrane covering the lung and lining 

the chest. There is one for each lung. 
Pleu^risy. An inflammation affecting the pleura. 
Pneu-mo-GAs'tric (Gr. nvev/nuv, pnieumon, the lungs, and yaarrjp, gaster, 

the stomach ; it is the principal nerve of respiration. 
Pneu-mo'nia (Gr. ). An inflammation aflecting the air-cells of the lungs. 
Pres-by'o'pi-A (Gr. npealSvg, presbus, old, and tj-tp, oj)s, the eye). A de- 
fect of the accommodation of the eye, caused by the hardening of the 

crystalline lens ; the "far-sight " of adults and aged persons. 
Proc'ess (L. proce'do, proccs'sus, to proceed, to go forth). Any projection 

from a surface. Also, a method of performance ; a procedure. 
Pty'a-lin (Gr. Trrvalov, j^tualon, saliva). The peculiar organic ingredient 

of the saliva. 
Pul'mo-na-ry (L. pul'mo, jnihno'nis, the lungs). Pertaining to the lungs. 
Pulse (L. pel'lo, pul'sum, to beat). The striking of an artery against the 

finger, occasioned by the contraction of the heart, commonly felt at the 

wrist. 



202 ■ GLOSSARY. 

Pu'i'iL (L. i^uinVla). The c^nt^al, round opening in the iris, through 

■which light passes into the depths of the e3^e. 
Py-lo'rus (L. TvvAupoc, imloros, a gate-keeper). The lower opening of 

the stomach, at the beginning of the small intestine. 
Re' FLEX Action. An involuntary action of the nervous system, by 

which an external impression conducted by a sensory nerve is reflected, 

or converted into a motor impulse. 
Res-pi-ra'tion (L. res'piro, to breathe frequently). The function of 

breathing, comprising two acts : inspiration, or breathing in, and 

expiration, or breathing out. 
Ret'ina (L. re'te, a net). The innermost of the three tunics or coats of 

the eyeball, being an expansion of the optic nerve. 
Sac'cha-rine (L. sad charum, sugar). Of the nature of sugar ; applied 

to the important group of food substances which embraces the ditierent 

varieties of sugar, starch, and gum. 
Sa-li'va (L. ). The moisture or fluids of the mouth, secreted by the 

salivary glands, etc. 
Scle-eot'ic (Gr. OK'Arjpog, sJdcros, hard). The tough, fibrous outer tunic 

of the eyeball. 
Se-ba'ceoits (L. sc'hum, fat). Resembling fat ; the name of the oily 

secretion by which the skin is kept flexible and soft. 
Se-cre'tiox (L. secer'no, secre'tum, to separate). The process of separat- 
ing from the blood some essential important fluid ; which fluid is also 

called a secretion. 
Sem-i-cir'cu-lar Canals. A portion of the internal ear. 
Sen-sa'tion. The perception of an external impression by the nervous 

system ; a function of the brain. 
Sen-si-bil'i-ty, General. The power possessed by nearly all parts of 

the human body of recognizing the presence of foreign objects that 

come in contact AAith them. . 
Se'rum (L. ). The watery constituent of the blood, which separates from 

the clot during the process of coagulation. 
Skel'e-ton (Gr. ). The bonj^ framework of an animal, the different parts 

of which are maintained in their proper relative positions. 
Spec'tro-scope (from spcc'trum and GKOTteo, scopeo, to examine the spec- 
trum). An instrument employed in the examination of the spectrum 

of the sun or any other luminous body. 
Sphyg'mo-graph (Gr. a<j)vyfi6c, sphugmos, the pulse, and ypd^u, grapho, 

to write). An ingenious instrument by means of which the pulse is 

delineated upon paper. 
St a' pes (L. ). Literally, a stirrup ; one of the small bones of the tympa- 
num, or middle ear, resembling somewhat a stirrup in shape. 



GLOSSARY. 203 

Sym-pa-thet'ic System of Nerves. A double chain of nervous gan- 
glia, connected together by numerous small nerves, situated chiefly in 
front of and on each side of the spinal column. 

Syn-o'via (Gr. ovv, sun, and cjov, oon, egg, resembling an egg). The 
lubricating fluid of joints, so called because it resembles the white of 

Sys'to-le (Gr. ova-ellu, sustcllo, to contract). The contraction of the 

heart by which the blood is expelled from that organ. 
Tac-tile (L. tac'tus, touch). Relating to the sense of touch. 
Tem'po-ral (L. tem'pus, time, and tem'pora, the temples). Pertaining to 

the temples ; the name of an artery : so called, because the hair begins 

to turn white with age in that portion of the scalp. 
Ten'don (L. tcn'do, to stretch). The white, fibrous cord or band by 

which a muscle is attached to a bone ; a sinew. 
Tet'a-nus (Gr. teIvu, teino, to stretch). A disease marked by persistent 

contractions of all or some of the voluntary muscles ; those of the jaw 

are sometimes solely affected, the disorder is then termed locked- 

jaw. 
Tho'rax (Gr. ■&C)pa^, tliorax, a breast-plate). The upper cavity of the 

trunk of the body, containing the lungs, heart, etc. ; the chest. 
Thy'roid (Gr. ■&vpe6^, thureos, a shield). The largest of the cartilages 

of the larynx ; its angular projection in the front of the neck is called 

"Adam's apple." 
Tra'che-a (Gr. rpaxvg, trachus, rough). The windpipe, or the largest of 

the air-passages ; composed in part of cartilaginous rings, which render 

its surface rough and uneven. 
Trans-fu'sion (L. transfun' do, to pour from one vessel to another). The 

operation of injecting blood taken from one person into the veins of 

another ; other fluids than blood are sometimes used. 
Trich-i'na Spi-ra'lis (L. ). A minute species of parasite or worm, which 

infests the flesh of the hog, and which may be introduced into the 

human system by eating pork not thoroughly cooked. 
Tym'pa-ntjm (Gr, rvjurrnvov, tumpanon, a drum). The cavity of the mid- 
dle ear, resembling a drum in being closed by two membranes, and in 

having communication with the atmosphere. 
U'vu-La (L. uva, a grape). The small pendulous body attached to the 

back part of the palate. 
Vas'ctj-lar (L. vas'culum, a little vessel). Pertaining to, or containing 

blood-vessels. 
Ve'nous (L. ve'na, a vein). Pertaining to, or contained within a vein. 
Ven-ti-la'tion. The introduction of fresh air into a room or building in 

such a manner as to keep the air within it in a pure condition. 



204 GLOSSARY. 

Ven-tril'o-quism (L. vcn^tcr, the belly, and lo'quor, to speak). A modi- 
fication of natural speech by which the voice is made to appear to come 
from a distance. The ancients supposed that the voice was formed in 
the belly ; hence the name. 

Yen'tri-cles of the heart. The two largest cavities of the heart, situ- 
ated at its apex or point. 

Yer'te-beal Column (L. ver'tebra, a joint). The back-bone, consisting 
of twenty-six separate bones, called vertebrae, firmly jointed together ; 
also called the spinal column and spine. 

Yes'ti-bule. a portion of the internal ear, communicating with the 
semicircular canals and the cochlea ; so called from its fancied resem- 
blance to the vestibule or porch of a house. 

Yil'li (L. vil'lus, the nap of cloth). Minute thread-like projections 
found upon the internal surface of the small intestine, giving it a vel- 
vety appearance. 

Yit'ee-ous (L. vi'triim, glass). Having the appearance of glass ; applied 
to the humor occupying the largest part of the cavity of the eye-ball, 

Yiy-i-sec'tion (L. vi'vus, alive, and se'co, to cut). The practice of operat- 
ing upon living animals, for the purpose of studying some physiological 
process. 

YocAL Cords. Two elastic bands or ridges situated in the lar}Tix ; they 
are the essential parts of the organs of the voice. 



INDEX. 



PAGE 

Absorbent vessels 70 

Absorption 69 

by blood-vessels 70 

b V the lacteals 70 

of the food 70 

Accommodation, Function of. 156 

Achilles, tendon of 24 

Acids, Poison from 177 

Adam's apple 169 

Air, Atmospheric 97 

Changes in, in respiration 97 

Carbonic acid in 101 

Composition of 97 

Dust in the 100 

Effects of impure 101 

Impurities in 99 

Matters in the expired 97 

Provision for purifying 102 

Renovation by ventilation 102 

Air-cells of the lungs 93 

Air-passages 92 

Albumen 43 

Albuminoid substances 43 

Varieties of 43 

Albuminose 68 

Alexis St. Martin 67 

Alcohol 50, 72, 87, 120 

as a fat-producer 88 

as a food 50 

a poison to the intellect 120 

and crime 122 

cold-promoting properties of 52 

Effects of, on digestion 72 

Effects of, upon the brain 120 

Effects of, upon the mind 120 

Effects of, upon the heart 87 

for thirst 52 

History of 50 

Hostility of, to life 54 

in the army 51 

Impairs the will 121 

Kinds of 50 

Properties of. 50 

Proper use of 54 

Trembling due to 120 

The poisonous effects of 122 

Alimentary canal 58 

Alkalies, Poisons 178 

Animal functions 106 

Animal heat 106 

how produced 104 

regulated by perspiration 104 

Animals, Relative strength of 35 



PAGE 

Antidotes 177 

Appendix 177 

Apoplexy 187 

Aqueous humor 150 

Arbor vitae , Ill 

Arterial blood 77 

differs from venous 99 

Arteries 83 

Arrangement of 82 

Distribution of. 82 

Pulsation of. 82 

Radial 83 

Table of 89 

Temporal 83 

Arytenoid cartilage 170 

Asphyxia ,. 180 

Assimilation 85 

Audition 157 

Auditory canal 160 

nerve 163 

Auricles of the heart 79 



Back -bone 

Bathing 

among the ancients 

Importance of 

Time and manner of 

Baths 

Different kinds of. 

Beer 

Bigelow, Dr. Jacob 

Bile 

Secretion of, in the liver 

Accumulation of, in the gall-bladder 

Uses of 

Black, J. R 

Bladder, Gall- 

Bleeding, how stopped 

Blood 

Arterial 

Change of color 

Circulation of 

Coagulation of 

Composition of 

corpuscles 

Course of 

fluid 

Microscoi)!c appearance of 

Respiratory changes in 

Uses of the 

Venous 

I Blood-vessels 



69 



206 



INDEX. 



PAGE 

Blood-vessels, Absorption by 70 

Injuries to the 87 

Body, renovation of the 40 

Movements of 23 

Bones 11 

Form and composition of 13 

Growth of 17 

Properties of. 13 

Eepair of 18 

Size and shape of 12 

Structure of. 12 

Uses of 11 

Brain 109 

Anatomical structure of. . . = 109 

Effects of alcohol upon 120 

Function of the 119 

Injuries of the 109 

Membranes of the 109 

Supply of blood to 109 

Tissue of 109 

Bread 47, 55 

and butter 47 

Bronchial tubes 93 

Burns 185 

Butter .... 43 

C. 

Caffeine '. 49 

Canals, Semicircular 1(53 

Capillary blood-vessels 84 

Circulation in the 85 

Carbonic acid 97 

exhaled from the lungs 99 

in the air 100 

Retention of, in the blood 101 

Cardiac 65 

Cartilage 16 

Arytenoid 170 

Cricoid 170 

Thyroid 170 

Caseine 44 

Cataract 153 

Cells, Nerve.... 107 

Cerebellum Ill 

Function of the 118 

Cerebro-spinal nervous system 108 

Cerebrum 109 

Function of the 119 

Chest, Framework of 14 

Chloral Hvdrate 126 

Effects of 126 

Chloroform. Use of 127 

Danger from 127 

Chocolate 49 

Choroid coat of the eye 150 

Chyle 69 

Chyme 68 

Cisarette smoking 125 

Circulation 75 

in the frog's foot 85 

of the blood 75 

Rapidity of 86 

through the heart 86 

through the lungs 86 

Clot rr 



PAGE 

Clothing 37 

Coagulation of the blood 77 

Coagulum 77 

Cochlea 163 

Coffee 49 

Effects of 49 

Colic, Painters' 38 

Collar-bone : 14 

Color-blindness 153 

Column, Spinal 17 

Complexion 33 

Concha of the ear . 160 

Conjunctiva 147 

Consciousness 131 

Contraction of heart 80 

of muscles 25 

Convulsions 187 

Cooking 45 

Cords, Vocal 170 

Cornea 150 

Corpuscles, Blood 76 

Cosmetics 38 

Cottntry 191 

On going into the 191 

Cranial nerves 112 

Cranium 109 

Cricoid cartilage 170 

Crystalline lens 153 

Uses of 154 

Cuticle 31 

Function of 135 

Cutis 32 

Cuts, Treatment of. 186 



D. 



Danger from opiates — 

Dark Ages. Persectttion in the , . . 

Davis, Judge Noah 

Dentition of infancy • 

De Quincy 

Diaphragm, Movements of the, 

respiration 

Diastole of the heart 

Diet. Mixed 

Necessity of a regulated 

Digestion 

Circumstances affecting 

Effects of Alcohol upon 

Gastric 

General plan of 

Intestinal 

Nature of 

Organs of . 

Disinfection 

Disinfectants 

Dover's Powders 

Drainage, House- 

City 

Drain diseases 

materials 

Drowning 

Drunkenness 

Drysdale. Dr. C. R 

Duct, Biliary , 

Nasal.., 



126 

190 
122 



95 

80 

55 

44 

57 

71 

72 

71 

57 

69 

67 

66 

183 

184 

125 

188 

189 

188 

189 

180 

121 

125 

69 

149 



INDEX. 



207 



PAGE 

Duct, Pancreatic 69 

Thoracic Tl 

E. 

Ear 159 

External 160 

Internal 163 

Middle 160 

Foreign bodies in the 166 

Drum of the 161 

Bones of the 161 

Ear-sand 164 

Earth-closets 191 

Earth-worm 131 

Ear-wax 160 

Eggs 45 

Composition of 45 

Emergencies 185 

Emotion 119 

Enamel of the teeth 58 

Epiglottis 170 

Uses of 170 

Eustachian tube 162 

Exercise 26 

Different modes of 26 

Effects of 26 

Excessive 27 

Importance of 26 

Open-air 27 

Expiration 96 

Movements of 96 

Eye 145 

Eveball 150 

Eyelashes 147 

Eyelids 147 

Eye-washes 88 

P. 

Fainting 187 

Father Matthew 122 

Fats 43 

Source of, in food 4;3 

Fenestra ovalis 164 

Fibres, Muscular 24 

Nervous 107 

Fibrillse 24 

Fibrine of the blood 76 

Fire 186 

Fits 187 

Fish, as food 47 

Flesh 23 

Flour 47 

Food 39 

Animal 45 

Daily quantity of 40 

Ingredients of 41, 43 

Necessity for 39 

Source of 40 

Vegetable 47 

Franklin on tobacco 125 

Frost-bites 186 

Fruits 48 

Benefits of 48 

Ripe 48 

Unripe. 48 



G. 

PAGE 

Gall-bladder 66-69 

Ganglia 107 

Gases, Interchange of, in the lungs. . 98 

Illuminating 186 

Gastric digestion 68 

Gastric juice 65 

Action of 66 

Daily quantity of 67 

General sensibility 132 

Glands, Perspiratory 34 

Salivary 62 

Sebaceous 34 

Glossary 193 

Glosso-phaiyngeal nerve 139 

Gullet 65 

Gustatory nerve.., 139 

H. 

Hand, The 135 

Hair , 33 

Uses of 33 

Hair-dyes 38 

Hare-lip 173 

Harvey, William 78 

Hasheesh 127 

Effects of 127 

Hasheeshers 127 

Hearing, Sense of 157 

Protection of 164 

Heart 78 

Cavities of the 79 

Circulation through the 80 

Frequency of action 81 

Movements of the 80 

Valves of the 81 

Heat, Animal 103 



Production of. 

Regulation of 

Hemispheres . . 

Impressions conveyed to. 



103 
104 



119 



Houses, location of 188 

House-waste 191 

Humor, Aqueous 150 

Crystalline lens 150 

Vitreous 150 

Hunger 39 

Hydra 107 

Hyperopia 155 



Ice-water, Effect upon digestion — 71 

Incus 161 

Inorganic substances in food 43 

Insalivation 62 

Insanity 121 

Insensible perspiration 33 

Inspiration 94 

Integument 31 

Intestinal juice 69 

Action of 69 

Intestinal digestion 69 

Intestines 68 

VilHof the 70 



208 



INDEX. 



PAGE 

Iris 151 

Function of 151 

J. 

Joints 14 

Motion in 16 

Juice, gastric 65 

Intestinal 69 

Pancreatic 69 

K. 

Kerosene 186 

Kinne, Dr. A. F 123 

I.. 

Labyrinth — 163 

Lachrymal canals 148 

gland 148 

point 149 

Lacteals , TO 

Absorption by 70 

Large intestines 6G 

Laryngoscope 172 

Larynx 93 

Production of the voice in the 169 

Laudanum 125 

Lavoisier 97 

Lens, Crystalline 153 

Ligaments 16 

Ligature 77 

Light, theory of. 145 

Lime in the bones 13 

Importance of 13 

Liquors, Adulteration in 54 

Liver 66-69 

Secretion of the 69 

Long-sight 155 

Lungs 91 

Structure of 92 

M, 

Malleus 161 

Marrow of the bones 12 

Mastication 58 

Importance of 58 

Meats 45 

Salted 45 

The cooking of 45 

The preservation of 45 

Membrane of the tympanum 161 

Medulla oblongata 112 

Function of the 118 

Mind, Eflfects of alcohol upon 120 

Milk 44 

Composition of ' 44 

Milk-teeth 9 

Morphine 125 

Mucous membrane 67 

Muscles 23 

Function of the 23 

Structure of 24 

Voluntary and involuntary 24 

Muscular contraction 25 



PAGE 

Muscular coat 67 

fibres 24 

sense 138 

Myopia 155 

W. 

Nails 33 

Uses of the 33 

Narcotics, Definition of 125 

Kinds of 125 

Property of 125 

Sleep produced by 127 

and digestion 128 

Nasal cavities 142 

duct 147 

Nerves 107 

Nerve, Auditory 163 

Glossopharyngeal 139 

Gustatory 139 

Olfactory 143 

Optic 145 

Sympathetic 114 

Nerve cells 107 

Nerve fibres 107 

Nerves, Cranial 112 

Spinal 113 

Functions of the 114 

Sensory, functions of the 115 

Motor, functions of the 115 

Sympathetic system of 114 

Nerve power 110 

Source of 110 

Nervous System 106 

Cerebro-spinal 109 

Nervous tissue, Properties of 114 

Composition of 107 

Nicotine 124 

Nose 142 

Nutrition, Processes of 57 

O. 

(Esophagus 65 

Oil, Sources of, in food 43 

Old-sight 157 

Olfactory nerve 143 

Opium 125 

how made 125 

in cigarettes 125 

Opiates, Effects of, on mind 126 

Danger from 126 

Effects on health 126 

Optic nerve 145 

Orbicular bone 161 

Orbit of the eye 146 

Organic substances as food 43 

Organs of circulation 78 

Digestion ; 57 

Respiration 91 

Sight 145 

Voice 169 

Ossicles 161 

Oxygen 97 

Amount of, consumed in respira- 
tion 97 



INDEX. 



209 



PAGE 

Oxygen, Continually supplied tc the 

atmosphere 98 

P. 

Pain, Eelations of. to pleasure 133 

Sensation of 133 

Uses of 133 

Pancreas 66-69 

Pancreatic juice 69 

Uses of 69 

Papiilte ... 135 

Paregoric 125 

Parepa Rosa 174 

Parke, Dr 87 

Passages, Air 92 

Pelvis 14 

Pepsin 67 

Perspiration, Daily amount of 35 

Sensible and insensible 34 

Uses of 35 

Perspiratory glands 34 

Physical strength 25 

Culture 26 

Pitch of sound 158 

Plasma of the blood 75 

Pleura 92 

Pneumo gastric nerve 118 

Poisons and their antidotes 177 

Poppy-plant 125 

Pork 45 

Posture 19 

Potato 48 

Presbyopia 157 

Preservation of the teeth, 60 

Ptyalin 63 

Pulsation of the heart 80 

of the arteries 82 

Pulse 82 

Pupil, The 151 

Pylorus 67 

R. 

Radial artery 83 

Red corpuscles of the blood 76 

Reflex action of the spinal cord 117 

Uses of 117 

Objects of.... 118 

Respiration 91 

Change of blood in 97 

Frequency of 96 

Movements of 94 

Object of 91 

Organs of 91 

Respiratory labor 99 

Rest, Necessity for 27 

Retina 152 

Retinal image 154 

Ribs, Movements of, in respiration. 94 

Ribot,Dr.T 127 

Saccharine substances 43 

Saliva 62 



PA.GE 

Saliva, Importance of 63 

Secretion of 62 

Salivary glands 62 

Salt, Common 42 

Importance of 43 

Salt-licks 43 

Scalds 185 

Scars from burns 185 

Sclerotic coat of the eyeball 150 

Sebaceous glands 34 

Secretion of. 34 

Semicircular canals 163 

Sensation of pain 133 

Relations of, to pleasure 133 

of temperature 138 

of weight 138 

Production of 130 

Variety of 131 

Sense of hearing 157 

sight 14i 

smell 142 

taste 139 

touch 135 

Sense, Muscular 1.38 

Thermal 138 

Senses, Special 130 

Sensibility, General 132 

Sewers 189 

Danger from 189 

Sewer-gas 189 

Prevention of 189 

Short-sight 155 

Sick-room, Care of the 181 

Sinews 24 

Sight, Sense of 144 

Organs of 145 

Skeleton 14 

Changes in 18 

Table of 20,21 

Skin 31 

Changes in 32 

Structure of 31 

Skull 14 

Uses of the 14 

Sleep, Necessity for 28 

Amount required 28 

produced by narcotics 127 

Small intestines 68 

Smell, Sense of 142 

Nerve of 142 

Uses of 143 

Smoking, Effects of 124 

Tremor due to 124 

Ci2:arette 125 

Snuff-taking 125 

Soil-pipe 1S9 

Soothing syrup 125 

Sound, Production of 157 

Special senses 130-134 

Speech 168 

Relation of, to the sense of hear- 
ing 169 

Spinal column 17 

Spinal cord 112 

Direction of fibres in 116 

Functions of the 116 



210 



INDEX. 



PAGE ] 

Spinal cord. Nerves of 113 i 

Reflex action of 117 : 

Spinal nerves 113 I 

Tissue of 113 

Spleen 66 

Spongioles ^ 70 ' 

Stapes 161 ' 

Starch 44 

Its change into sugar 44 

Different kinds 44! 

Microscopic appearance 44 

Stimulation, Effects of mild 122 

Stomacli 58-65 

Digestion 57 j 

Movements of 67 

Secretion of. 66 

Strength. Physical 25 ' 

Sugar...: 43 

Varieties 43 ! 

Sources of 43 

Sun-bath 37 

Sunstroke 187 i 

Sympathetic svstem of nerves 114 ! 

Systole of the heart 80 

T. 

Tactus eruditus 137 

Tartar 52 

Taste, Association of 140 

Education of. 141 

Organ of 138 

Sense of 139 

Tea, Effect of 49 

Tears 148 

Escape of the 149 

Secretion of 149 

Teeth 58 

Temporary set of 59 

Permanent set of 59 

Bicuspids 59 

Caniue ! 59 

Incisor 59 

Molar 59 

Arrangement of 59 

of different animals 60 

Preservation of , 61 

Temperature of the body 103 

Extremes of. 104 

Sensations of 108 

Tendon of Achilles 24 

Tendons 24 

Tiieine 49 

Theobroma 49 

Thermie 37 

Thirst 39 

Thoracic duct 71 

Thorax 71 

Thought 119 

Throat deafness 163 

Thvroid cartilage 169 

Tickling 132 

Tobacco r« 

as a poison 12:3 

effects upon young 124 

in Military and Naval Academies. 124 



PAGE 

Tobacco, when in training 124 

Tongue 138 

Nerves of 139 

Sensibility 139 

Touch, Delicacy of 136 

Organs of 134 

Sense of 135 

Trachea 92 

Trap 189 

water 191 

Trichina spiralis 46 

Trunk 14 

Tympanum of the ear 160 

Membrane of 161 



Valves of the heart 81 

of the veins 84 

Vapor, Animal, in breath 97 

V ■ 



"eal. 



45 



Vegetable food 47 

respiration 106 

Vegetative functions 106 

Veins 83 

Valves of 84 

Venous blood 77 

Changes of, in respiration 99 

Ventilation 102 

Ventricles of the larynx 170 

of the heart ! 79 

Ventriloquism 174 

Vertebrae 17 

Vertigo 187 

Vestibule of the internal ear 163 

Villi of the intestines 70 

Absorprion by 70 

Vitreous humor 150 

Vocal cords 170 

Observation of, with laryngo- 
scope 171 

Voice 168 

Organ of 169 

Production of 172 

Varieties of 173 

W. 

Waste-pipes 189 

Water-seal .189, 191 

Water-closet 191 

Water 41 

Action of, on lead 42 

Chemically pure 42 

exhaled with the breath 97 

from springs and wells 42 

Pure 41 

Walking, as a means of exercise 26 

Well, care of the 190 

Pollution of 190 

White corpuscles of the blood 76 

Wine 51 

Will, impairment of. 121 

Winking 149 

Wisdom teeth 59 

Wrist-drop 3fc' 



QUESTIONS 



BONES, 

What comparison is made between a bouse and the buman body ? 

Wbat are tbe uses of tbe bones? 

How are tbe brains and lungs protected ? 

Wbat can you tell about tbe size and sbape of tbe bones ? 

Describe tbe structure of tbe bones ? 

Of wbat substances are tbe bones composed ? 

Wbat is tbe effect of fire upon tbe bones ? 

Wbat is tbe effect of removing tbe mineral ingredient ? 

Wby do tbe bones of old people break more readily tban tbose of 
tbe young? 

How are tbe bones adapted to tbe purposes tbey are designed to 
serve ? 

How many bones are there in tbe body ? 

Wbat are tbey called wben united ? 

Wbat is tbe skull ? Tbe cbest ? Tbe pelvis ? 

Wbat do tbe two latter compose ? 

How are tbe skull and trunk kept in position ? 

How are tbe arms attached to tbe cbest ? 

Wbat do the skull, cbest, and trunk each protect ? 

Wbat is a joint ? 

By wbat are the movable joints connected ? 

Describe the ligaments ? 

Is an injury to tbem serious ? 

How are the joints enabled to move easily? 

Is the fluid about the joints self-supplied ? 

Wbat is tbe spinal col umn ? 

How does it protect the brain from injury ? 

Do tbe bones change ? 

How can you prove it by experiments ? 



212 QUESTIONS. 

What is tlie process for unitino^ broken bones ? 

Will the bone ever be as strong as before it was broken '? 

How do the bones change after a man is twenty -five ? 

How do children become bow-legged ? 

What habits of standing and sitting should be formed in youth ? 



MUSCLES. 

What are the muscles, and their use? 

How many are there ? 

What are the tendons ? 

What is the largest tendon of the body ? 

Describe the structure of the muscles ? 

Into what two classes are they divided ? 

Is the heart a muscle ? 

What is muscular contraction ? 

Can a muscle remain long contracted ? 

In proportion to size is a horse as powerful as a man ? 

Are insects as powerful ? 



To what is strength in a great measure du 



Is exercise essential to the development of the muscles, and what is 
its effect upon the heart, skin, and brain ? 
Should it be violent or excessive ? 
Is rest important after labor? 
What effect does sleep have ? 
Do all persons require the same amount ? 
What effects follow an insufficient amount of sleep ? 



THE SKIN. 



What is the skin, and what is its use? 

Wliat is its structure ? 

Describe the cuticle, or scarf skin ? 

What is the cutis, or true skin ? 

Can they be separated ? 

Does the skin change, and why? 

What can you say about the nails ? 

What about the hair ? 

What causes the difference in complexion? 

What are the sebaceous orlands ? 



QUESTIONS. 213 

Wliat are tlie perspiratory glands ? 

What is insensible perspiration ? 

What is sensible perspiration ? 

What can you say of the uses and importance of perspiration ? 

What experiments illustrate this ? 

Is it important to bathe often, and why ? 

Is it best to use perfumes or soap and water ? 

When is a cold bath best ? 

When a warm one ? 

What is the best time to bathe ? 

Is a sun-bath beneficial ? 

What effect does the want of sunlight have upon plants ? 

Is it necessary to have warm clothing- ? 

Why are cosmetics injurious ? 

Are hair dyes injurious? 

FOOD AND DRINK 

Why is there a necessity for food ? 

How long can man exist without food ? 

How long on water alone ? 

Does the quantity of food vary for diflferent individuals ? 

What is the quantity for a healthy man ? 

How often is the body renewed ? 

What does the term food include? 

How are the substances we use as food classified ? 

What are organic substances ? Inorganic? 

What part of the body is water? 

Where is it found ? 

Which can man remain without the longer, food or water ? 

What is tlie purest water in nature ? 

Is water from springs and wells pure ? 

How does lead affect water ? 

Are lead pipes injurious ? 

How is salt obtained ? 

How is the importance of salt shown ? 

What effect does the loss of salt have upon animals ? 

Mention the organic food substances. 

Where is fat most used as food ? 

What kind of food is most used in hot climat(^s ? 

Are sugars producers of heat ? 



214 QUESTIONS. 

What is the proportion of starch in breadstuffs ? 

Are these three food-groups essential to life ? 

Can an animal be starved on any one of these ? 

Will milk sustain life ? Why ? 

What should be eaten ^s^-ith eggs, and Why ? 

Why should meats be eaten ? 

Is salted meats as nutritious as fresh ? Wliy ? 

What is the object of cooking ? 

How should you boil meat for food ? For soup ? 

What is the best method of cooking meat ? 

What is the effect of frying ? 

Should any form of pork be eaten raw ? 

What disease does raw pork often produce ? 

Is fish easily digested ? 

Are all products of the vegetable kingdom useful ? 

What flour makes the best bread ? 

What form of bread is most easily digested ? 

Is hot bread wholesome ? 

Is bread and butter a wholesome diet ? 

Is bread alone ? 

What can you say of the potato ? 

Is ripe fruit beneficial ? Unripe ? 

Is coffee of use, and what effect has it ? 

Does it take the place of food ? 

What effect has tea ? Chocolate ? 

What is said of the origin of the word Alcohol ? 

From what was alcohol first made ? 

What is said of common alcohol, how and from what substances is 
it obtained? 

Describe its properties ? 

Is it nourishing- when used as food ? 

Are rations of grog in the army or navy of service to the men ? 

Does alcohol relieve thirst ? 

How do alcoholic drinks seem to quench thirst ? 

What effects produced by its use are observed after death ? 

Does alcohol enable those who use it to bear cold better than those 
who abstain from it ? 

What is the result of the tests by the thermometer ? 

How do persons who use it seem to be w armer ? 

How do you know that this impression is a delusion ? 

What is the cause of the flashing of the face common to hard 
drinkers ? 



QUESTIONS. 215 

Is death hastened in cold regions by the use of alcohol ? 
Give instances where the experiment has been tried ? 
Is alcohol hostile to life ? 

Gtive instances where it is fatal to plants and animals? 
How can it be used with benefit to man ? 



DIGESTION. 

Through what changes must food pass to nourish the body ? 

What is the alimentary canal, and what is its use ? 

What is mastication ? 

Describe the teeth, and their uses ? 

How many have children ? Adults ? 

What are their names? 

How do the teeth of animals differ? 

How must you take care of the teeth ? 

What is tartar, and how can you prevent it ? . 

Is enamel, when destroyed, ever formed anew? 

What is the use of the saliva ? 

How is It secreted? 

Does rapid eating interfere with digestion ? How ? 

How does the food get into the stomach ? 

How many openings has the stomach ? 

What are their names and uses ? 

What is the gastric juice ? What is its use ? 

How IS it furnished ? 

Of what use is the muscular coat ? 

How have the workings of the stomach of a man been seen ? 

Is the food entirely digested in the stomach ? 

Describe the process. 

What are the intestines ? 

How do they assist digestion ? 

What is the bile ? The pancreatic juice ? 

What are tlieir uses ? 

What is the intestinal juice ? 

How is absorption accomplished ? 

What are the lacteal s, and their uses ? 

What length of time is required for the digestion of food ? 

What kinds of food are most easily digested ? 

What is the effect of ice water upon the stomach? 

Does strong emotion check digestion ? 



216 QUESTIONS. 

What other causes affect it ? 
Is it best to eat often ? 

How does exercise directly after eating affect digestion? Should 
you sleep directly after eating ? 

What are the effects of alcohol upon the stomach? 
How are other organs affected by it ? 

CIRCULATION OP BLOOD. 

Is blood important to the body? 

What is the total quantity in the body? 

What is the color ? The odor ? 

How does the blood appear under the microscope ? 

What are the blood corpuscles ? 

How many are there in a cubic inch of blood ? 

How does the blood look after standing exposed ? 

How does coagulation prevent death ? 

What is the use of the blood ? 

How and for what reason does the blood change its co'or ? 

Is the blood in motion ? 

By whom was the circulation of the blood discovered ? 

Of what use is the heart ? Where situated ? 

Describe it. 

How many cavities has it ? What are they ? 

Which side carries the venous and which the arterial blood ? 

Are its movements voluntary ? 

In what does its action consist ? 

Trace the passage of the blood through the heart ? 

What is the general direction of the heart-currents ? 

Describe the action of the ventricles and auricles ? 

What are the heart-beats ? 

How many in a minute for an adult ? 

What are the causes which increase or diminish its action ? 

What influence have mental emotions ? 

Do they ever cause death ? 

What is the amount of blood moved in one minute ? In a lifetime ? 

What are the arteries ? Describe them. 

Are they full or empty after death ? 

Describe the arterial system. 

What is the pulse, and where can you feel it ? 

How is the pulse an index of health or sickness ? 



QUESTIONS. 217 

What are the veins, and what their size ? 

How do you distinguish them from the arteries ? 

How do you prove that the direction of venous blood is towards the 
heart ? 

Which are nearest the surface, the veins or arteries? 

What are the capillaries, and their use ? 

Describe the circulation of blood in a frog's foot. 

Is the supply of capillaries abundant in all parts of the body ? 

To what is the blood-shot appsarance of the eye due when irritated? 

How do you prove that the blood moves with great rapidity ? 

In what time does the blood make a complete round of the circula- 
tion? 

By what are supplies furnished to the different parts of the body ? 

What is assimilation ? The most favorable time for it ? 

Which is more dangerous, haemorrhage from an artery or a vein? 

How can it be stopped in each ? 

What is the effect of alcohol upon the heart ? 

Does it increase strength ? 

What was the result of Dr. Parke's experiments ? 

Does alcohol increase flesh ? 

What is the fat which is accumulated by drinking ? 

What is its effect upon the blood ? 

RESPIRATION. 

What is the object of respiration ? 
What are the special organs of respiration ? 
How many are they, and where situated ? 
Describe the substance of the lungs. 
What is the pleura, and its use ? 
How is it attached, and how is it kept moist ? 

How do the lungs communicate with the external air? What is 
the longest tube ? , 

How is this tube divided in the chest ? 

What are the bronchial tubes ? 

Are these tub^s flexible? How strengthened ? 

Where is the larynx situated? 

What is it, and what its use ? 

What covers the top of the larynx, and what is its use ? 

What is the effect if food passes into the larynx ? 

What keeps the air passages moist ? • » 



218 QUESTIONS. 

What is inspiration ? What is expiration ? 

What effect has inspiration on the chest ? 

What is the diaphragm, and its special power ? 

How does the diaphragm assist in expiration ? 

How often do we breathe ? 

How long can you hold your breath ? 

If necessary, how can you make the time longer? 

Is air a simple element ? How is it formed ? 

Are these gases alike ? 

Can air be breathed a second time? 

What eflPect has impure air upon animals ? Upon light ? 

What is the gas that the lungs exhale ? 

What is the vapor given off by the lungs ? 

What change takes place in the passage of the blood through the 
lungs ? 

How do you prove that this change is dependent upon respiration ? 

What gas is the food for the blood ? 

What causes sufEocation ? 

By what are the air and blood separated? 

How do the two gases exchange places ? 

Does the temperature of the blood vary ? 

How often do we breathe in a minute ? 

How many cubic inches of air pass in and out of the lungs with 
every breath ? 

What do bad odors indicate, and against what do they guard us ? 

Is man's breath impure? 

What care should people take who nurse the sick ? 

What effect do filters of cotton wool have ? 

How is carbonic acid produced in our houses ? 

What effect does impure air have ? 

Does it produce consumption ? 

Does impure air affect animals? Give instances. 

How does nature purify the air ? 

How shall we ventilate our houses ? 

What is the temperature of the human body ? 

How is it regulated ? 

THE NERVOUS SYSTEM. 

What name is given to the ilunctions of digestion, circulation, and- 
respiration ? Why so called ? 



QUESTIONS. 219 

What has tho animal in addition ? 

If a hydra be cut in pieces, what properties has each jjiece? 

Of what is the nervous tissue composed ? 

When the tissue is examined under the microscope, what do you 
find ? 

Which substance predominates ? 

What part of the nervous system is concerned in the animal func- 
tions ? 

What is the other set of organs called ? 

What is the brain ? What is its shape ? 

How many parts, and what are they ? 

How is the brain protected ? 

How much blood is sent to the brain ? 

What is the cerebrum ? How divided ? 

How is the surface divided ? 

What is the true source of nervous power ? 

What is the cerebellum ? 

What is the medulla oblongata ? 

What are the cranial nerves, and how many of them are there ? 

Describe the spinal cord. 

Is this an important part ot the system ? 

Where do the spinal nerves originate ? 
How are these nerves hardened and strengthened? 

Is there a difference in the sensations communicated by different 
nerves ? Example. 

Describe the sympathetic system ? 

What is the difference in the uses of the gray and white substances? 

Of what two functions of the system are the nerves the instruments? 

How do you prove that there are two sets of fibres in the nerves ? 

Can a limb be injured so that it will retain motion and lose sensa- 
tion? 

What columns of the spinal cord are concerned in motion and sen- 
sation ? 

Is the spinal cord the true centre of sensation ? 

If one lateral half of the spinal cord be injured, what fact is ob- 
served ? 

What course do the motor fibres pursue ? 

What the sensory fibres ? 

What is the reflex action of the cord ? • ' 

What are the uses of that action ? 

What reflex motions take place in certain involuntary muscles? 

What are the objects of reflex action ? 



^20 QUESTIONS. 

What are the functions of the medulla oblongata ? 

Of the cerebellum ? 

Of the cerebrum ? 

Do great men possess large brains ? 

What mental acts are developed through the action of the brain ? 

What are the effects of alcohol upon the brain ? 

What are its effects on the mind ? 

What is its effect upon the will ? 

Is this habit once formed hard to break? 

What is the effect of drunkenness upou man ? 

What was proved, by the labors of Father Matthew, with regard to 
the advantages of temperance ? 

What are the poisonous effects of alcohol upon man ? 

What is its effect as a stimulant ? 

Describe tobacco ? 

What use is made of it ? 

What effect has it upon the young ? 

How is it hurtful to adults ? 

What are the effects of its limited use ? 

What of its prolonged use ? 

What is the testimony of the naval and military academies as to its 
effects upon the young men ? 

What have been the advantages of its prohibition ? 

How is cigarette smoking particularly injurious ? 

How is snuff-taking injurious ? 

To what substances is the term narcotic applied ? 

Which are next in importance to alcohol ? 

What is opium ? 

What is its active principle ? 

VThat are the effects of this principle upon the system? 

What is its use ? 

What danger to be feared from the use of Dover's Powders, Sooth 
ing Svrups, etc.? 

What is the effect of the habitual use of opium? 

From w^hat is chloral hydrate produced? 

What are its effects, and the danger of its use ? 

What is Hasheesh ? 

For what is it used ? 

What is chloroform ? 

For what is it used ? 

What are its dangers ? 

Ought narcotics to be used without proper medical advice ? 



QUESTIONS. 221 



THE SPECIAL SENSES. 

Where is tlie true centre of sensation ? 

Does the mind receive impressions at that point, or to what points 
are they referred ? 

What faculty of the brain is necessary to complete a sensation ? 

Do you receive sensations when asleep ? 

Have all animals sensibility ? 

Has man more or less than animals ? 

What is the lowest form of sensation ? 

The highest form ? 

How are sensations modified by use ? 

What is general insensibility ? 
• What is the most painful part of a surgical operation ? Why ? 

Are all impressions received from without ? 

What is pain ? 

What is the difference between sensibility and pain, as illustrated 
by the effect of sunlight ? 

What are the uses of pain ? 

What are the special senses ? 

Are special organs furnished? 

Can the eye hear or the ear see ? 

What other sense do some writers give us ? 

Where do you find the sense of touch most developed ? 

What is the office of the cuticle, as illustrated by the hand ? 

Does the sense of touch assist other senses ? 

How do you illustrate it ? 

Which sense is least liable to error ? 

How do you illustrate the delicacy of touch ? 

Is it acquired by practice ? 

What can you say of the sensations of temperature and weight ? 

What is the organ of taste ? 

Tell how it receives sensations. 

What nerve at the back of the tongue ? 

What conditions are necessary to the sense of taste ? 

Do all parts of the tongue perceive equally the same fl.avors ? 

Does the sense of taste affect internal organs ? 

Is taste a simple sense ? 

Upon what other sense is taste dependent 'I Illustrate it. 

What is the use of taste ? 



222 QUESTIONS. 

Are articles tliat gratify the taste of a cLild generally wholesome? 
Where is the sense of smell located ? 
What nerves endow the nose with sensibility ? 
What are the uses of smell ? 
Does it aid us in the choice of food ? 
What is the sense of sight ? 

Does sight bring us into contact with the bodies examined? 
What gives this sense its wide range ? 
What is the undulatory theory ? 

What is that part of the eye sensitive to the waves of light ? 
Has science done anything to prevent blindness ? 
Does the loss of one eye impair sight ? 
How is the eyeball protected from injury ? 
What use are the eye' ids ? 
What is the conjunctiva, and its uses ? 
What are the uses of the sebaceous glands ? 
Where is the lachrymal gland situated ? 
What is the use of it ? 
By what duct are the tears carried off ? 
What is the use in moistening the eye by tears ? 
What is the shape of the eyeball ? 
Of what is it composed ? 
Name the three coats of the eyeball. 
Describe them. 

What is the iris, and of what use is it ? 
Does it regulate the admission of light ? . 

W^hat is the retina? 

Are impressions made upon it at once lost ? Give examples. 
What is color blindness? 
What is the crystalline lens ? 
What is cataract ? 

What are the uses of the crystalline lens? 

As the image upon the retina is inverted, how do we see objects in 
their true position ? 

What is the cause of short sight ? Of long sight ? 

Has the eye the capacity of adjusting itself to distances? 

How is the eye affected by old age ? 

What is sound ? How is it propagated ? 

Is the earth a good conductor of sound ? 

Upon what does the pitch of the sounds depend ? 

Into what three portions is the ear divided ? 



QUESTIONS. 223 

Of what two parts is tlie external ear composed ? 

Describe the auditory canal. 

Of what use is ear-wax ? 

What is the middle ear ? 

What is the membrana tvmpani? 

What is the eustachian tube ? 

Where is the auditory nerve found ? 

What is the most essential part of the organ of hearing? 

Of how many parts does the labyrinth consist ? 

What is ear-sand ? 

How many nerves have been couuted in the cochlea ? 

How is sound conveyed to the brain? 

Does cold water injure the ear ? 

Is cold air hurtful to the ear ? 

What effect upon the ear do solid substances have ? 

How can you remove foreign objects from the ear ? 



THE VOICE. 

How are the sounds which animals make produced ? Of insects ? 
What is the difference between the speech of parrots and men ? 
Is speech related to hearing ? 
Why is a child born deaf also dumb ? 
What is the essential organ of the voice ? 
Where is it situated, and of what composed ? 
Give the names of the cartilages. 
With what is the larynx lined ? 

To what is the epiglottis attached ? What is its office ? 
What are the vocal cords ? Describe them. 
If one or both cords are injured, what is the effect ? 
In ordinary breathing, is any sound produced ? 
What enables us to recognize a person by his speech ? 
Are the teeth, lips, and tongue important in speech? 
How many varieties of voice are there ? What are they ? 
When does the voice change ? 
What change is there in the larynx ? 
What is the ordinary range of the voice ? 
Can the vocal organs be trained? What is the effect? 
What is ventriloquism ? 

What are the mysterious responses of the ancient oracles thought 
to have been ? 



r 



0^:=-^ 

^ ~ ^ i 

Text-Book on Bhetorio; 

Supplementing the Development of the Science with 
Exhaustive Practice in Composition. 

A COFESE OF PEACTICAL LESSONS ADAPTED POE USE m HIGH-SCHOOLS 
"and AGADEitlES AND IN TEE LOWEE CLASSES OP COLLEGES. 

By BRAINEUD KELLOG-G-, A.M., 

Profeaaor of the English Language and Literature in the Brooklyn Collegiate 

and Polytechnic Institute, and one of the authors of Beed & Kellogg's 

*' Graded Leeaona in English** and ^^ Higher Lessons in English." 

In preparing this work upon Rhetoric, the author's aim has been to 
write a practical text-book for High-Schools, Academies, and the lower 
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through eye and ear, but by drawing it out of him, in products, through 
tongue and pen. Hence all explanations of principles are followed by 
exhaustive practice in Composition — to this everything is made tributary. 

When, therefore, under the head of Invention, the author is leading 
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through the analyses of subjects and the preparing of frameworks, to 
the finding of the thought for-themes ; when, under the head of Style, 
he is familiarizing the pupil with its grand, cardinal qualities ; and when, 
under the head of Productions, he divides discourse into oral prose, writ- 
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quisites and functions of each — he is aiming in it all to keep sight of the 
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into almost endless practice with his pen what he has learned from the 
study of the theory. 

276 pages, l^mo, aUracUvely hound in cloth. 

PUBLISHED BY 

Clark & MATNAED, 734: Broadway, New York. 



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